Based on considerable progress made in understanding the Cosmic Microwave Background (CMB) temperature from a deep theoretical perspective, this paper demonstrates a useful and simple relationship between the CMB temp...Based on considerable progress made in understanding the Cosmic Microwave Background (CMB) temperature from a deep theoretical perspective, this paper demonstrates a useful and simple relationship between the CMB temperature and the Hubble constant. This allows us to predict the Hubble constant with much higher precision than before by using the CMB temperature. This is of great importance, since it will lead to much higher precision in various global parameters of the cosmos, such as the Hubble radius and the age of the universe. We have improved uncertainty in the Hubble constant all the way down to 66.8712 ± 0.0019 km/s/Mpc based on data from one of the most recent CMB studies. Previous studies based on other methods have rarely reported an uncertainty much less than approximately ±1 km/s/Mpc for the Hubble constant. Our deeper understanding of the CMB and its relation to H0seems to be opening a new era of high-precision cosmology, which may well be the key to solving the Hubble tension, as alluded to herein. Naturally, our results should also be scrutinized by other researchers over time, but we believe that, even at this stage, this deeper understanding of the CMB deserves attention from the research community.展开更多
This paper discusses the “Hubble constant measurement—mystery”. Independent measurements of this cosmic parameter, referred to as <i><span style="font-family:Verdana;">H</span></i>...This paper discusses the “Hubble constant measurement—mystery”. Independent measurements of this cosmic parameter, referred to as <i><span style="font-family:Verdana;">H</span></i><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> in abbreviated form, have all led to different values, with the highest value ≈ 74 km<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and the lowest ≈ 67 km<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, where km denotes kilometer, s second and Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> megaparsec. These measurements have mainly been obtained with space telescopes. Apparently, up to now there was no way to explain the differences. However, previously published studies seem to regard the problem of the different measurement results for </span><i><span style="font-family:Verdana;">H</span></i><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> [</span><span style="font-family:Verdana;"><a href="#ref1">1</a>,</span><b><span style="font-family:Verdana;"> </span></b><span style="font-family:Verdana;"><a href="#ref2">2</a></span><span style="font-family:Verdana;">]. I have shown that due to a symmetrical expansion of the Minkowski space (SMS), each respective frame of reference for an observer, who rests in the zero point of the frame, is converted into a state of apparent rest relative to the cosmic microwave background (CMB) radiation. This SMS-relativistic effect also seems to be responsible for the different measurement results of the Hubble constant, especially through space telescopes.</span>展开更多
Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble co...Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.展开更多
General Relativity implies an expanding Universe from a singularity, the so-called Big Bang. The rate of expansion is the Hubble constant. There are two major ways of measuring the expansion of the Universe: through t...General Relativity implies an expanding Universe from a singularity, the so-called Big Bang. The rate of expansion is the Hubble constant. There are two major ways of measuring the expansion of the Universe: through the cosmic distance ladder and through looking at the signals originated from the beginning of the Universe. These two methods give quite different results for the Hubble constant. Hence, the Universe doesn’t expand. The solution to this problem is the theory of gravitation in flat space-time where space isn’t expanding. All the results of gravitation for weak fields of this theory agree with those of General Relativity to measurable accuracy whereas at the beginning of the Universe the results of both theories are quite different, i.e. no singularity by gravitation in flat space-time and non-expanding universe, and a Big Bang (singularity) by General Relativity.展开更多
Different measurements of the Hubble constant(H_(0))are not consistent,and a tension between the CMB based methods and cosmic distance ladder based methods has been observed.Measurements from various distance based me...Different measurements of the Hubble constant(H_(0))are not consistent,and a tension between the CMB based methods and cosmic distance ladder based methods has been observed.Measurements from various distance based methods are also inconsistent.To aggravate the problem,the same cosmological probe(TypeⅠa SNe for instance)calibrated through different methods also provides different values of H_(0).We compare various distance ladder based methods through the already available unique data obtained from the Hubble Space Telescope(HST).Our analysis is based on parametric(t-test)as well as non-parametric statistical methods such as the Mann-Whitney U test and Kolmogorov-Smirnov test.Our results show that different methods provide different values of H_(0) and the differences are statistically significant.The biases in the calibration would not account for these differences as the data have been taken from a single telescope with a common calibration scheme.The unknown physical effects or issues with the empirical relations of distance measurement from different probes could give rise to these differences.展开更多
This work continues the previous study (2018) Journal of Modern Physics. 9, 1827-1837, that proposes that the disagreement arises because the cosmic microwave background (CMB) value for the Hubble constant <em>H...This work continues the previous study (2018) Journal of Modern Physics. 9, 1827-1837, that proposes that the disagreement arises because the cosmic microwave background (CMB) value for the Hubble constant <em>H</em><sub><em>0</em></sub> is actually for a universe which is decelerating rather than accelerating. It is shown that when <em>H</em><sub><em>0</em></sub> of Freedman et al. (2019) Astrophysical Journal, 882: 34 (24 pp.) is re-determined for redshift <em>z </em>= 0.07, by replacing <em>q</em><sub><em>0 </em></sub>= <span style="white-space:nowrap;">−</span>0.53 with <em style="white-space:normal;">q</em><sub style="white-space:normal;"><em>0 </em></sub><span style="white-space:normal;">= <span style="white-space:nowrap;">−</span>0.5</span>, the new lower value is in excellent agreement (0.1%) with the CMB <em>H</em><sub><em>0</em></sub>. The model is modified to include the clustering of galaxies, and the recognition that there are clusters that do not experience the Hubble expansion, such as the Local Group, and hence, in accordance with the model, within the Local Group the speed of light is <em>c</em>. The bearing of this result on the neutrino and light time delay from SN1987a is discussed. It is suggested that the possible emission of a neutrino from the blazar TXS-0506+56, that was flaring at the time, as well as possible neutrino emission earlier, may arise instead from a more distant source that happens to be, angle-wise, near the blazar, and hence the correlation is accidental. The model is further modified to allow for a variable index of refraction, and a comparison with the ΛCDM model is given. The age of the universe for different values of<em> H</em><sub><em>0</em></sub> is studied, and comparison with the ages of the oldest stars in the Milky Way is discussed. Also, gravitational wave determination of <em>H</em><sub><em>0</em></sub> is briefly discussed.展开更多
Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves w...Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves within a million years, SNes occurring in a rarified environment outside of the ISM generate blast waves which remain in a relativistic free expansion phase for more extended periods. The SN blast wave forms an expanding spherical shell and when multiple blast waves intersect, the overlapping region naturally takes the form of a ring, an arc, or an Einstein Cross structure. The analysis shows the relativistic plasma establishes a medium with permeability which drives the index of refraction greater than 1. As a result, when a shock discontinuity forms in the overlapping region, light is reflected from the host galaxy which exposes the intersecting blast wave regions. The expanding shells are shown to induce an achromatic redshift to the reflected light consistent with those measured for gravitational lenses. Further, it is shown that a Hubble equation for a blast wave around the Milky Way Galaxy can be parameterized to approximate measured redshifts over a wide range of distances.展开更多
Through an analytical approach, we show that the Hubble constant is not unique and has two distinct values. The first of these values is consistent with the measurements by Riess et al., while the second value is cons...Through an analytical approach, we show that the Hubble constant is not unique and has two distinct values. The first of these values is consistent with the measurements by Riess et al., while the second value is consistent with the measurements by the Planck Collaboration. This is a new alternative approach that does not depend on the standard ΛCDM model and its constraints. Our analysis shows that the tension is due to a geometric mismatch in the comparison of the measurements which is equal to the temporal diameter of the surface of last scattering. Since the calculated values are essentially identical to the corresponding measured values, we conclude that the non-congruency of the ending point of the Riess et al. measurement and the starting point of the Planck Collaboration measurement, on the surface of last scattering, is the source of tension in the measurements. Further, the surprising consistency of the calculated values of the Hubble constant with the corresponding measured values confirms both the extreme fidelity of the measurements and the validity of the proposed approach.展开更多
<p> Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant <em>...<p> Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant <em>H</em><sub><em>0</em></sub>. We want to validate our theoretical value of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 72.09548580(32) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span>s<span style="white-space:nowrap;"><span style="white-space:nowrap;"><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></sup></span></span><sup>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup> with a new cosmological model found in 2019. This model predicts what may look like two possible values of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub>. According to this model, the correct equation of the apparent age of the universe gives ~ 14.14 billion years. In approximation, we get the well-known equation 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 13.56 billion years. When we force these ages to fit the 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> formula, it gives two different Hubble constant values of ~69.2 and 72.1 km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span><span style="white-space:nowrap;">sdot;</span></span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup>. When we apply a theoretical correction factor of <em>η</em> ≈ 1.042516951 on the first value, both target the second one. We found 42 equations of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> linking different physics constants. Some are used to measure <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> as a function of the average temperature<em> T</em> of the Cosmological Microwave Background and the universal gravitational constant <em>G</em>: </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.06(90) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<span style="vertical-align:super;white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span><sup>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> from <em>T </em>by Cobra probe & Equation (16) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 71.95(50) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1 </sup>from<em> T</em> by Partridge & Equation (16) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.086(36) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-1 </span></span></span></sup>from <em>G</em> & Equation (34) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.105(36) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> from <em></em><em>G</em> & Equations (74), (75), or (76). With 508 published values, <em>H</em><sub><em>0</em></sub> ≈ 72.0957 ± 0.33 km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> seems to be the “ideal” statistical result. It validates our model and our theoretical <em>H</em><sub><em>0</em></sub> value which are useful to find various interactions with the different constants. Our model also explains the ambiguity between the different universe’s age measurements and seems to unlock a tension between two <em>H</em><sub><em>0</em></sub> values. </p>展开更多
The Hubble constant H0,a key parameter quantifying the present expansion rate of the universe,remains a subject of significant debate due to the persistent tension between early-and late-universe measurements.Strong g...The Hubble constant H0,a key parameter quantifying the present expansion rate of the universe,remains a subject of significant debate due to the persistent tension between early-and late-universe measurements.Strong gravitational lensing(SGL) time delays provide an independent avenue to constrain H0.In this paper,we utilize seven SGL systems from the TDCOSMO sample to constrain H_(0),employing the model-independent approaches:deep neural networks(DNN),Gaussian process(GP),polynomial fitting(polyfit) and Padé approximant(PA).Using these methods,we reconstruct unanchored luminosity distances from the Pantheon+SNe Ia dataset and obtain H_(0)=72.3_(-3.6)^(+3.8)km s^(-1)Mpc^(-1),H_(0)=72.4_(-1.7)^(+1.6)km s^(-1)Mpc^(-1),H0=70.7_(-3.1)^(+3.0)km s^(-1)Mpc^(-1)and H0=74.0_(-2.7)^(+2.7)km s^(-1)Mpc^(-1),respectively.These estimates are consistent within 1σ level and align with local distance ladder results.Notably,the GP method achieves uncertainties that are half those of the DNN approach,whereas the DNN method offers more reliable confidence intervals in reconstruction at high redshifts.Our findings underscore the potential of these methodologies to refine constraints on H_(0) and contribute to resolving the Hubble tension with future advancements.展开更多
Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cos...Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary coalescences.Using these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.展开更多
In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole bina...In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological parameters.For the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and Q3nod.Our results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision cosmology.Moreover,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy models.When combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN data.We also consider a conservative scenario in which EM counterparts are not available.Due to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.展开更多
Fast radio bursts(FRBs)are useful cosmological probes with numerous applications in cosmology.The distribution of the dispersion measurement contribution from the intergalactic medium is a key issue.A quasi-Gaussian d...Fast radio bursts(FRBs)are useful cosmological probes with numerous applications in cosmology.The distribution of the dispersion measurement contribution from the intergalactic medium is a key issue.A quasi-Gaussian distribution has been used to replace the traditional Gaussian distribution,yielding promising results.However,this study suggests that there may be additional challenges in its application.We used 35 well-localized FRBs to constrain the Hubble constant H_(0)along with two FRB-related parameters,yielding H_(0)=■The best-fitting Hubble constant H_(0)is smaller than the value obtained from the Cosmic Microwave Background(CMB),which may be caused by the small sample size of current FRB data.Monte Carlo simulations indicate that a set of 100 simulated FRBs provides a more precise fitting result for the Hubble constant.However,the precision of the Hubble constant does not improve when further enlarging the FRB sample.Additional simulations reveal a systematic deviation in the fitting results of H_(0),attributed to the quasi-Gaussian distribution of the dispersion measure in the intergalactic medium.Despite this,the results remain reliable within 1σuncertainty,assuming that a sufficient number of FRB data points are available.展开更多
Even though the Hubble constant cannot be significantly determined just by the low-redshift Baryon Acoustic Oscillation(BAO)data, it can be tightly constrained once the high-redshift BAO data are combined. We combined...Even though the Hubble constant cannot be significantly determined just by the low-redshift Baryon Acoustic Oscillation(BAO)data, it can be tightly constrained once the high-redshift BAO data are combined. We combined BAO data from 6d FGS, BOSS DR11 clustering of galaxies, Wiggle Z and z = 2.34 from BOSS DR11 quasar Lyman-α forest lines to get H0= 68.17+1.55-1.56 km s-1Mpc-1. In addition, we adopted the simultaneous measurements of H(z) and DA(z) from the two-dimensional two-point correlation function from BOSS DR9 CMASS sample and two-dimensional matter power spectrum from SDSS DR7 sample to obtain H0=(68.11±1.69) km s-1Mpc-1. Finally, combining all of the BAO datasets, we conclude that H0=(68.11±0.86) km s-1Mpc-1, a1.3% determination.展开更多
Gravitational wave signal from the inspiral of stellar-mass binary black hole can be used as standard sirens to perform cosmological inference.This inspiral covers a wide range of frequency bands,from the millihertz b...Gravitational wave signal from the inspiral of stellar-mass binary black hole can be used as standard sirens to perform cosmological inference.This inspiral covers a wide range of frequency bands,from the millihertz band to the audio-band,allowing for detections by both space-borne and ground-based gravitational wave detectors.In this work,we conduct a comprehensive study on the ability to constrain the Hubble constant using the dark standard sirens,or gravitational wave events that lack electromagnetic counterparts.To acquire the redshift information,we weight the galaxies within the localization error box with photometric information from several bands and use them as a proxy for the binary black hole redshift.We discover that Tian Qin is expected to constrain the Hubble constant to a precision of roughly 30%through detections of 10 gravitational wave events;in the most optimistic case,the Hubble constant can be constrained to a precision of<10%,assuming Tian Qin I+II.In the optimistic case,the multi-detector network of Tian Qin and LISA is capable of constraining the Hubble constant to within 5%precision.It is worth highlighting that the multi-band network of Tian Qin and Einstein Telescope is capable of constraining the Hubble constant to a precision of about 1%.We conclude that inferring the Hubble constant without bias from photo-z galaxy catalog is achievable,and we also demonstrate self-consistency using the P-P plot.On the other hand,high-quality spectroscopic redshift information is crucial for improving the estimation precision of Hubble constant.展开更多
In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of t...In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H<sub>0</sub>. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned.展开更多
This paper introduces the two Upsilon constants to the reader. Their usefulness is described with respect to acting as coupling constants between the CMB temperature and the Hubble constant. In addition, this paper su...This paper introduces the two Upsilon constants to the reader. Their usefulness is described with respect to acting as coupling constants between the CMB temperature and the Hubble constant. In addition, this paper summarizes the current state of quantum cosmology with respect to the Flat Space Cosmology (FSC) model. Although the FSC quantum cosmology formulae were published in 2018, they are only rearrangements and substitutions of the other assumptions into the original FSC Hubble temperature formula. In a real sense, this temperature formula was the first quantum cosmology formula developed since Hawking’s black hole temperature formula. A recent development in the last month proves that the FSC Hubble temperature formula can be derived from the Stephan-Boltzmann law. Thus, this Hubble temperature formula effectively unites some quantum developments with the general relativity model inherent in FSC. More progress towards unification in the near-future is expected.展开更多
An analytical method to calculate Hubble’s constant [1] is presented. The proposed procedure is an alternative scheme to the red shifts of spectral lines picture, to obtain the value of that constant [2].
In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a ser...In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a series of cosmological predictions can be derived solely from two constants, namely the Planck length and the speed of gravity. The speed of gravity can be easily determined without knowledge of the speed of light [1] [2]. This provides a new perspective on cosmology and demonstrates that there is a link between the Planck scale and cosmology. This is fully consistent with a recent quantization of general relativity theory that links general relativity to the Compton frequency and the Planck scale. We examine both the Friedmann cosmology and the recently introduced cosmology based on the extremal solution of the Reissner-Nordström, Kerr, and Kerr-Newman metric.1.展开更多
The results of measurements of the Hubble constant H<sub>0</sub>, which characterizes the expansion rate of the universe, show that the values of H<sub>0</sub> vary significantly depending on M...The results of measurements of the Hubble constant H<sub>0</sub>, which characterizes the expansion rate of the universe, show that the values of H<sub>0</sub> vary significantly depending on Methodology. The disagreement in the values of H<sub>0</sub> obtained by the various teams far exceeds the standard uncertainties provided with the values. This discrepancy is called the Hubble Tension. In this paper, we discuss Macrostructures of the World (Superclusters and Galaxies);explain their Origin and Evolution in frames of the developed Hypersphere World-Universe Model (WUM), which is an alternative to the prevailing Big Bang Model (BBM) [1];and provide the explanation of the Hubble Tension. The main difference between WUM and BBM is: Instead of the Infinite Homogeneous and Isotropic Universe around the Initial Singularity in BBM, in WUM, the 3D Finite Boundless World (a Hypersphere) presents a Patchwork Quilt of different Luminous Superclusters (10<sup>3</sup>), which emerged in various places of the World at different Cosmological times. In WUM, the Medium of the World is Homogeneous and Isotropic. The distribution of Macroobjects in the World is spatially Inhomogeneous and Anisotropic and temporally Non-simultaneous.展开更多
文摘Based on considerable progress made in understanding the Cosmic Microwave Background (CMB) temperature from a deep theoretical perspective, this paper demonstrates a useful and simple relationship between the CMB temperature and the Hubble constant. This allows us to predict the Hubble constant with much higher precision than before by using the CMB temperature. This is of great importance, since it will lead to much higher precision in various global parameters of the cosmos, such as the Hubble radius and the age of the universe. We have improved uncertainty in the Hubble constant all the way down to 66.8712 ± 0.0019 km/s/Mpc based on data from one of the most recent CMB studies. Previous studies based on other methods have rarely reported an uncertainty much less than approximately ±1 km/s/Mpc for the Hubble constant. Our deeper understanding of the CMB and its relation to H0seems to be opening a new era of high-precision cosmology, which may well be the key to solving the Hubble tension, as alluded to herein. Naturally, our results should also be scrutinized by other researchers over time, but we believe that, even at this stage, this deeper understanding of the CMB deserves attention from the research community.
文摘This paper discusses the “Hubble constant measurement—mystery”. Independent measurements of this cosmic parameter, referred to as <i><span style="font-family:Verdana;">H</span></i><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> in abbreviated form, have all led to different values, with the highest value ≈ 74 km<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and the lowest ≈ 67 km<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, where km denotes kilometer, s second and Mpc</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> megaparsec. These measurements have mainly been obtained with space telescopes. Apparently, up to now there was no way to explain the differences. However, previously published studies seem to regard the problem of the different measurement results for </span><i><span style="font-family:Verdana;">H</span></i><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> [</span><span style="font-family:Verdana;"><a href="#ref1">1</a>,</span><b><span style="font-family:Verdana;"> </span></b><span style="font-family:Verdana;"><a href="#ref2">2</a></span><span style="font-family:Verdana;">]. I have shown that due to a symmetrical expansion of the Minkowski space (SMS), each respective frame of reference for an observer, who rests in the zero point of the frame, is converted into a state of apparent rest relative to the cosmic microwave background (CMB) radiation. This SMS-relativistic effect also seems to be responsible for the different measurement results of the Hubble constant, especially through space telescopes.</span>
文摘Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.
文摘General Relativity implies an expanding Universe from a singularity, the so-called Big Bang. The rate of expansion is the Hubble constant. There are two major ways of measuring the expansion of the Universe: through the cosmic distance ladder and through looking at the signals originated from the beginning of the Universe. These two methods give quite different results for the Hubble constant. Hence, the Universe doesn’t expand. The solution to this problem is the theory of gravitation in flat space-time where space isn’t expanding. All the results of gravitation for weak fields of this theory agree with those of General Relativity to measurable accuracy whereas at the beginning of the Universe the results of both theories are quite different, i.e. no singularity by gravitation in flat space-time and non-expanding universe, and a Big Bang (singularity) by General Relativity.
文摘Different measurements of the Hubble constant(H_(0))are not consistent,and a tension between the CMB based methods and cosmic distance ladder based methods has been observed.Measurements from various distance based methods are also inconsistent.To aggravate the problem,the same cosmological probe(TypeⅠa SNe for instance)calibrated through different methods also provides different values of H_(0).We compare various distance ladder based methods through the already available unique data obtained from the Hubble Space Telescope(HST).Our analysis is based on parametric(t-test)as well as non-parametric statistical methods such as the Mann-Whitney U test and Kolmogorov-Smirnov test.Our results show that different methods provide different values of H_(0) and the differences are statistically significant.The biases in the calibration would not account for these differences as the data have been taken from a single telescope with a common calibration scheme.The unknown physical effects or issues with the empirical relations of distance measurement from different probes could give rise to these differences.
文摘This work continues the previous study (2018) Journal of Modern Physics. 9, 1827-1837, that proposes that the disagreement arises because the cosmic microwave background (CMB) value for the Hubble constant <em>H</em><sub><em>0</em></sub> is actually for a universe which is decelerating rather than accelerating. It is shown that when <em>H</em><sub><em>0</em></sub> of Freedman et al. (2019) Astrophysical Journal, 882: 34 (24 pp.) is re-determined for redshift <em>z </em>= 0.07, by replacing <em>q</em><sub><em>0 </em></sub>= <span style="white-space:nowrap;">−</span>0.53 with <em style="white-space:normal;">q</em><sub style="white-space:normal;"><em>0 </em></sub><span style="white-space:normal;">= <span style="white-space:nowrap;">−</span>0.5</span>, the new lower value is in excellent agreement (0.1%) with the CMB <em>H</em><sub><em>0</em></sub>. The model is modified to include the clustering of galaxies, and the recognition that there are clusters that do not experience the Hubble expansion, such as the Local Group, and hence, in accordance with the model, within the Local Group the speed of light is <em>c</em>. The bearing of this result on the neutrino and light time delay from SN1987a is discussed. It is suggested that the possible emission of a neutrino from the blazar TXS-0506+56, that was flaring at the time, as well as possible neutrino emission earlier, may arise instead from a more distant source that happens to be, angle-wise, near the blazar, and hence the correlation is accidental. The model is further modified to allow for a variable index of refraction, and a comparison with the ΛCDM model is given. The age of the universe for different values of<em> H</em><sub><em>0</em></sub> is studied, and comparison with the ages of the oldest stars in the Milky Way is discussed. Also, gravitational wave determination of <em>H</em><sub><em>0</em></sub> is briefly discussed.
文摘Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves within a million years, SNes occurring in a rarified environment outside of the ISM generate blast waves which remain in a relativistic free expansion phase for more extended periods. The SN blast wave forms an expanding spherical shell and when multiple blast waves intersect, the overlapping region naturally takes the form of a ring, an arc, or an Einstein Cross structure. The analysis shows the relativistic plasma establishes a medium with permeability which drives the index of refraction greater than 1. As a result, when a shock discontinuity forms in the overlapping region, light is reflected from the host galaxy which exposes the intersecting blast wave regions. The expanding shells are shown to induce an achromatic redshift to the reflected light consistent with those measured for gravitational lenses. Further, it is shown that a Hubble equation for a blast wave around the Milky Way Galaxy can be parameterized to approximate measured redshifts over a wide range of distances.
文摘Through an analytical approach, we show that the Hubble constant is not unique and has two distinct values. The first of these values is consistent with the measurements by Riess et al., while the second value is consistent with the measurements by the Planck Collaboration. This is a new alternative approach that does not depend on the standard ΛCDM model and its constraints. Our analysis shows that the tension is due to a geometric mismatch in the comparison of the measurements which is equal to the temporal diameter of the surface of last scattering. Since the calculated values are essentially identical to the corresponding measured values, we conclude that the non-congruency of the ending point of the Riess et al. measurement and the starting point of the Planck Collaboration measurement, on the surface of last scattering, is the source of tension in the measurements. Further, the surprising consistency of the calculated values of the Hubble constant with the corresponding measured values confirms both the extreme fidelity of the measurements and the validity of the proposed approach.
文摘<p> Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant <em>H</em><sub><em>0</em></sub>. We want to validate our theoretical value of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 72.09548580(32) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span>s<span style="white-space:nowrap;"><span style="white-space:nowrap;"><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></sup></span></span><sup>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup> with a new cosmological model found in 2019. This model predicts what may look like two possible values of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub>. According to this model, the correct equation of the apparent age of the universe gives ~ 14.14 billion years. In approximation, we get the well-known equation 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 13.56 billion years. When we force these ages to fit the 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> formula, it gives two different Hubble constant values of ~69.2 and 72.1 km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span><span style="white-space:nowrap;">sdot;</span></span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup>. When we apply a theoretical correction factor of <em>η</em> ≈ 1.042516951 on the first value, both target the second one. We found 42 equations of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> linking different physics constants. Some are used to measure <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> as a function of the average temperature<em> T</em> of the Cosmological Microwave Background and the universal gravitational constant <em>G</em>: </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.06(90) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<span style="vertical-align:super;white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span><sup>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> from <em>T </em>by Cobra probe & Equation (16) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 71.95(50) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1 </sup>from<em> T</em> by Partridge & Equation (16) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.086(36) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-1 </span></span></span></sup>from <em>G</em> & Equation (34) </p> <p> <em>H</em><sub><em>0</em></sub> ≈ 72.105(36) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> from <em></em><em>G</em> & Equations (74), (75), or (76). With 508 published values, <em>H</em><sub><em>0</em></sub> ≈ 72.0957 ± 0.33 km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>s<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span>1</sup> seems to be the “ideal” statistical result. It validates our model and our theoretical <em>H</em><sub><em>0</em></sub> value which are useful to find various interactions with the different constants. Our model also explains the ambiguity between the different universe’s age measurements and seems to unlock a tension between two <em>H</em><sub><em>0</em></sub> values. </p>
文摘The Hubble constant H0,a key parameter quantifying the present expansion rate of the universe,remains a subject of significant debate due to the persistent tension between early-and late-universe measurements.Strong gravitational lensing(SGL) time delays provide an independent avenue to constrain H0.In this paper,we utilize seven SGL systems from the TDCOSMO sample to constrain H_(0),employing the model-independent approaches:deep neural networks(DNN),Gaussian process(GP),polynomial fitting(polyfit) and Padé approximant(PA).Using these methods,we reconstruct unanchored luminosity distances from the Pantheon+SNe Ia dataset and obtain H_(0)=72.3_(-3.6)^(+3.8)km s^(-1)Mpc^(-1),H_(0)=72.4_(-1.7)^(+1.6)km s^(-1)Mpc^(-1),H0=70.7_(-3.1)^(+3.0)km s^(-1)Mpc^(-1)and H0=74.0_(-2.7)^(+2.7)km s^(-1)Mpc^(-1),respectively.These estimates are consistent within 1σ level and align with local distance ladder results.Notably,the GP method achieves uncertainties that are half those of the DNN approach,whereas the DNN method offers more reliable confidence intervals in reconstruction at high redshifts.Our findings underscore the potential of these methodologies to refine constraints on H_(0) and contribute to resolving the Hubble tension with future advancements.
基金supported by the National SKA Program of China (Grant Nos.2022SKA0110200, and 2022SKA0110203)the National Natural Science Foundation of China (Grant Nos. 11975072, 11875102, and 11835009)+1 种基金the science research grants from the China Manned Space Project (Grant No. CMS-CSST-2021-B01)the 111 Project (Grant No. B16009)。
文摘Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary coalescences.Using these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.
基金supported by the National SKA Program of China(Grant Nos.2022SKA0110200,and 2022SKA0110203)the National Natural Science Foundation of China(Grant Nos.11975072,11875102,and 11835009)+1 种基金the National 111 Project(Grant No.B16009)the Fundamental Research Funds for the Central Universities(Grant No.N232410019)。
文摘In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological parameters.For the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and Q3nod.Our results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision cosmology.Moreover,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy models.When combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN data.We also consider a conservative scenario in which EM counterparts are not available.Due to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.
基金Supported by the National Natural Science Fundation of China(12275034)the Fundamental Research Funds for the Central Universities of China(2023CDJXY-048)。
文摘Fast radio bursts(FRBs)are useful cosmological probes with numerous applications in cosmology.The distribution of the dispersion measurement contribution from the intergalactic medium is a key issue.A quasi-Gaussian distribution has been used to replace the traditional Gaussian distribution,yielding promising results.However,this study suggests that there may be additional challenges in its application.We used 35 well-localized FRBs to constrain the Hubble constant H_(0)along with two FRB-related parameters,yielding H_(0)=■The best-fitting Hubble constant H_(0)is smaller than the value obtained from the Cosmic Microwave Background(CMB),which may be caused by the small sample size of current FRB data.Monte Carlo simulations indicate that a set of 100 simulated FRBs provides a more precise fitting result for the Hubble constant.However,the precision of the Hubble constant does not improve when further enlarging the FRB sample.Additional simulations reveal a systematic deviation in the fitting results of H_(0),attributed to the quasi-Gaussian distribution of the dispersion measure in the intergalactic medium.Despite this,the results remain reliable within 1σuncertainty,assuming that a sufficient number of FRB data points are available.
基金supported by the Project of Knowledge Innovation Program of Chinese Academy of Science,National Natural Science Foundation of China(Grant Nos.11322545 and 11335012)
文摘Even though the Hubble constant cannot be significantly determined just by the low-redshift Baryon Acoustic Oscillation(BAO)data, it can be tightly constrained once the high-redshift BAO data are combined. We combined BAO data from 6d FGS, BOSS DR11 clustering of galaxies, Wiggle Z and z = 2.34 from BOSS DR11 quasar Lyman-α forest lines to get H0= 68.17+1.55-1.56 km s-1Mpc-1. In addition, we adopted the simultaneous measurements of H(z) and DA(z) from the two-dimensional two-point correlation function from BOSS DR9 CMASS sample and two-dimensional matter power spectrum from SDSS DR7 sample to obtain H0=(68.11±1.69) km s-1Mpc-1. Finally, combining all of the BAO datasets, we conclude that H0=(68.11±0.86) km s-1Mpc-1, a1.3% determination.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001)the National Natural Science Foundation of China(Grant Nos.12173104,11805286,and 11690022)the National Key Research and Development Program of China(Grant No.2020YFC2201400)。
文摘Gravitational wave signal from the inspiral of stellar-mass binary black hole can be used as standard sirens to perform cosmological inference.This inspiral covers a wide range of frequency bands,from the millihertz band to the audio-band,allowing for detections by both space-borne and ground-based gravitational wave detectors.In this work,we conduct a comprehensive study on the ability to constrain the Hubble constant using the dark standard sirens,or gravitational wave events that lack electromagnetic counterparts.To acquire the redshift information,we weight the galaxies within the localization error box with photometric information from several bands and use them as a proxy for the binary black hole redshift.We discover that Tian Qin is expected to constrain the Hubble constant to a precision of roughly 30%through detections of 10 gravitational wave events;in the most optimistic case,the Hubble constant can be constrained to a precision of<10%,assuming Tian Qin I+II.In the optimistic case,the multi-detector network of Tian Qin and LISA is capable of constraining the Hubble constant to within 5%precision.It is worth highlighting that the multi-band network of Tian Qin and Einstein Telescope is capable of constraining the Hubble constant to a precision of about 1%.We conclude that inferring the Hubble constant without bias from photo-z galaxy catalog is achievable,and we also demonstrate self-consistency using the P-P plot.On the other hand,high-quality spectroscopic redshift information is crucial for improving the estimation precision of Hubble constant.
文摘In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H<sub>0</sub>. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned.
文摘This paper introduces the two Upsilon constants to the reader. Their usefulness is described with respect to acting as coupling constants between the CMB temperature and the Hubble constant. In addition, this paper summarizes the current state of quantum cosmology with respect to the Flat Space Cosmology (FSC) model. Although the FSC quantum cosmology formulae were published in 2018, they are only rearrangements and substitutions of the other assumptions into the original FSC Hubble temperature formula. In a real sense, this temperature formula was the first quantum cosmology formula developed since Hawking’s black hole temperature formula. A recent development in the last month proves that the FSC Hubble temperature formula can be derived from the Stephan-Boltzmann law. Thus, this Hubble temperature formula effectively unites some quantum developments with the general relativity model inherent in FSC. More progress towards unification in the near-future is expected.
文摘An analytical method to calculate Hubble’s constant [1] is presented. The proposed procedure is an alternative scheme to the red shifts of spectral lines picture, to obtain the value of that constant [2].
文摘In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a series of cosmological predictions can be derived solely from two constants, namely the Planck length and the speed of gravity. The speed of gravity can be easily determined without knowledge of the speed of light [1] [2]. This provides a new perspective on cosmology and demonstrates that there is a link between the Planck scale and cosmology. This is fully consistent with a recent quantization of general relativity theory that links general relativity to the Compton frequency and the Planck scale. We examine both the Friedmann cosmology and the recently introduced cosmology based on the extremal solution of the Reissner-Nordström, Kerr, and Kerr-Newman metric.1.
文摘The results of measurements of the Hubble constant H<sub>0</sub>, which characterizes the expansion rate of the universe, show that the values of H<sub>0</sub> vary significantly depending on Methodology. The disagreement in the values of H<sub>0</sub> obtained by the various teams far exceeds the standard uncertainties provided with the values. This discrepancy is called the Hubble Tension. In this paper, we discuss Macrostructures of the World (Superclusters and Galaxies);explain their Origin and Evolution in frames of the developed Hypersphere World-Universe Model (WUM), which is an alternative to the prevailing Big Bang Model (BBM) [1];and provide the explanation of the Hubble Tension. The main difference between WUM and BBM is: Instead of the Infinite Homogeneous and Isotropic Universe around the Initial Singularity in BBM, in WUM, the 3D Finite Boundless World (a Hypersphere) presents a Patchwork Quilt of different Luminous Superclusters (10<sup>3</sup>), which emerged in various places of the World at different Cosmological times. In WUM, the Medium of the World is Homogeneous and Isotropic. The distribution of Macroobjects in the World is spatially Inhomogeneous and Anisotropic and temporally Non-simultaneous.
