期刊文献+
共找到70篇文章
< 1 2 4 >
每页显示 20 50 100
Gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld spacetime with a cosmic string
1
作者 Xin-Fei Li Lei-Hua Liu +2 位作者 Yan-Zhi Meng Shu-Qing Zhong Li-Juan Zhou 《Communications in Theoretical Physics》 2025年第12期110-118,共9页
In this work we study gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld(EiBI)spacetime that incorporates with a cosmic string.It is found that the presence of a cosmic string can enhance the... In this work we study gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld(EiBI)spacetime that incorporates with a cosmic string.It is found that the presence of a cosmic string can enhance the light deflection in the strong-field limit,compared to the Ellis–Bronnikov wormhole.The magnification effects of this composite structure could cause some substantial impacts on the angle separation between the first and the rest of the images,and their relative brightness.Furthermore,based on these observables,we model some observable aspects in the strong-and the weak-field limits.The presence of a cosmic string can affect some distinguishable observables compared to the wormhole without cosmic string.This work could deepen our understanding of the spacetime structure of the wormhole in EiBI spacetime with one-dimensional topological defects. 展开更多
关键词 cosmic string gravitational lensing Eddington-inspired Born-Infeld spacetime
原文传递
The Gravitational Constant G May Decrease between Millimetre-Sized Masses
2
作者 Qinghua Cui 《Journal of Modern Physics》 2025年第1期133-139,共7页
The Newtonian gravitational constant G is one of the most important fundamental constants of nature, but still remains resistant to the standard model of physics and disconnected from quantum theory. During the past &... The Newtonian gravitational constant G is one of the most important fundamental constants of nature, but still remains resistant to the standard model of physics and disconnected from quantum theory. During the past >100 years, hundreds of G values have been measured to be ranging around 6.66 to 6.7559 × 10−11 m3·kg−1·s−2 using macroscopic masses. More recently, however, a G value ((6.04 ± 0.06) × 10−11 m3·kg−1·s−2) measured using millimetre-sized masses shows significant deviation (by ~9%) from the reference G value, which the authors explained is resulted from “the known systematic uncertainties”. However, based on the observation of historical G values and the protocol of the millimetre-sized masses based experiment, here we proposed a theory that this deviation is not from “systematic uncertainties” but actually G will rapidly decrease when masses sphere diameter is less than 0.02 metres. Moreover, this theory predicted the G value will be 5.96 × 10−11 m3·kg−1·s−2 between masses whose diameter are 2 millimetres (0.002 metres), which matches the measured G value very well. 展开更多
关键词 gravitY gravitational Constant cosmic Microwave Background DIFFRACTION
在线阅读 下载PDF
Cosmic Constraints to the wCDM Model from Strong Gravitational Lensing
3
作者 安洁 常葆荣 徐立昕 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期191-195,共5页
We study the cosmic constraint to the wCDM (cold dark matter with a constant equation of state w) model via 118 strong gravitational lensing systems which are compiled from SLA CS, BELLS, LSD and SL2S surveys, where... We study the cosmic constraint to the wCDM (cold dark matter with a constant equation of state w) model via 118 strong gravitational lensing systems which are compiled from SLA CS, BELLS, LSD and SL2S surveys, where the ratio between two angular diameter distances Dobs =DA(Zl, Zs ) / D A ( O, Zs ) is taken as a cosmic observable. To obtain this ratio, we adopt two strong tensing models: one is the singular isothermal sphere model (SIS) and the other one is the power-law density profile (PLP) model. Via the Markov chain Monte Carlo method, the posterior distribution of the cosmological model parameters space is obtained. The results show that the cosmological model parameters are not sensitive to the parameterized forms of the power-law index γ. Furthermore, the PLP model gives a relatively tighter constraint to the cosmological parameters than that of the SIS model. The predicted value of Ωm = 0.31+0.44 -0.24 by the SIS model is compatible with that obtained by P1anck2015: Ωm = 0.313 ± 0.013. However, the value of Ωm =0.15+0.13 -0.11 based on the PLP model is smaller and has 1.25σ tension with that obtained by Planck2015. 展开更多
关键词 of on it from cosmic Constraints to the wCDM Model from Strong gravitational Lensing SIS is PLP that PLANCK into been
原文传递
Ratio of Gravitational Force to Electric Force from Empirical Equations in Terms of the Cosmic Microwave Background Temperature
4
作者 Tomofumi Miyashita 《Journal of Modern Physics》 2024年第5期674-689,共16页
Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among... Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (T<sub>c</sub>) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10<sup>−11</sup> m<sup>3</sup>∙kg<sup>−1</sup>∙s<sup>−2</sup>, respectively. Every equation could be explained in terms of the Compton length of an electron (λ<sub>e</sub>), the Compton length of a proton (λ<sub>p</sub>) and a. Furthermore, every equation could also be explained in terms of Avogadro’s number and the number of electrons in 1 C. However, the ratio of the gravitational force to the electric force cannot be uniquely determined when the unit of the Planck constant (Js) is changed. In this study, we showed that every equation can be described in terms of Planck constant. From the assumption of minimum mass, the ratio of gravitational force to electric force could be elucidated. 展开更多
关键词 Ratio of gravitational Force to Electric Force Minimum Mass Temperature of the cosmic Microwave Background
在线阅读 下载PDF
Possible Relations of Cosmic Microwave Background with Gravity and Fine-Structure Constant 被引量:2
5
作者 Qinghua Cui 《Journal of Modern Physics》 CAS 2022年第7期1045-1052,共8页
Gravity is the only force that cannot be explained by the Standard Model (SM), the current best theory describing all the known fundamental particles and their forces. Here we reveal that gravitational force can be pr... Gravity is the only force that cannot be explained by the Standard Model (SM), the current best theory describing all the known fundamental particles and their forces. Here we reveal that gravitational force can be precisely given by mass of objects and microwave background (CMB) radiation. Moreover, using the same strategy we reveal a relation by which CMB can also precisely define fine-structure constant α. 展开更多
关键词 gravitY gravitational Constant cosmic Microwave Background Fine-Structure Constant
暂未订购
5D World-Universe Model. Gravitation 被引量:11
6
作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 2016年第3期328-343,共16页
5D World-Universe Model is based on the decisive role of the Medium of the World composed of massive particles: protons, electrons, photons, neutrinos, and dark matter particles. In this manuscript we discuss differen... 5D World-Universe Model is based on the decisive role of the Medium of the World composed of massive particles: protons, electrons, photons, neutrinos, and dark matter particles. In this manuscript we discuss different aspects of the gravitation: measured values of the Newtonian parameter of Gravitation and different Gravitational effects (gravitational lensing, cosmological redshift, gravitational deflection of light and gravitational refraction, proposed in the present paper). We show inter-connectivity of all cosmological parameters and provide a mathematical framework that allows direct calculation of them based on the value of the gravitational parameter. We analyze the difference between Electromagnetism and Gravitoelectromagnetism and make a conclusion about the mandatory existence of the Medium of the World. This paper aligns the World-Universe Model with the Le Sage’s theory of gravitation and makes a deduction on Gravity, Space and Time be emergent phenomena. 展开更多
关键词 5D World-Universe Model Newtonian Parameter of gravitation Le Sage’s gravity cosmic Neutrino Background gravitoelectromagnetism Medium of the World Cosmological Parameters Emergent Phenomena
在线阅读 下载PDF
Flat Space Cosmology as a Model of Penrose’s Weyl Curvature Hypothesis and Gravitational Entropy
7
作者 Eugene Terry Tatum 《Journal of Modern Physics》 2018年第10期1935-1940,共6页
FSC is shown to be an excellent model of Penrose’s Weyl curvature hypothesis and his concept of gravitational entropy. The assumptions of FSC allow for the minimum entropy at the inception of the cosmic expansion and... FSC is shown to be an excellent model of Penrose’s Weyl curvature hypothesis and his concept of gravitational entropy. The assumptions of FSC allow for the minimum entropy at the inception of the cosmic expansion and rigorously define a cosmological arrow of time. This is in sharp contrast to inflationary models, which appear to violate the second law of thermodynamics within the early universe. Furthermore, by virtue of the same physical assumptions applying at any cosmic time t, the perpetually-flat FSC model predicts the degree of scale invariance observed in the CMB anisotropy pattern, without requiring an explosive and exceedingly brief inflationary epoch. Penrose’s concepts, as described in this paper, provide support for the idea that FSC models gravitational entropy and Verlinde’s emergent gravity theory. 展开更多
关键词 FLAT Space COSMOLOGY COSMOLOGY Theory gravitationAL ENTROPY Weyl’s Curvature HYPOTHESIS Black Holes cosmic Inflation cosmic Flatness cosmic Microwave Background
在线阅读 下载PDF
How the CMB Anisotropy Pattern Could Be a Map of Gravitational Entropy
8
作者 Eugene Terry Tatum 《Journal of Modern Physics》 2018年第8期1484-1490,共7页
The rationale for Flat Space Cosmology (FSC) calculations of gravitational entropy in the form ofis presented. These calculations indicate a tight correlation with the COBE DMR measurement showing CMB RMS temperature ... The rationale for Flat Space Cosmology (FSC) calculations of gravitational entropy in the form ofis presented. These calculations indicate a tight correlation with the COBE DMR measurement showing CMB RMS temperature variations of 18 micro Kelvins. The COBE dT/T anisotropy ratio of 0.66 × 10&minus;5 falls within the FSC gravitational entropy range calculated for the beginning and ending conditions of the recombination/decoupling epoch. Thus, the FSC model incorporating gravity as an emergent property of entropy suggests that the CMB temperature anisotropy pattern could simply be a map of gravitational entropy, as opposed to a magnified “quantum fluctuation” event at a finite beginning of time. 展开更多
关键词 Flat Space COSMOLOGY cosmic Microwave Background CMB ANISOTROPY COSMOLOGY Theory cosmic ENTROPY gravitationAL ENTROPY Black Holes Standard COSMOLOGY
在线阅读 下载PDF
Explanation of the Necessity of the Empirical Equations That Relate the Gravitational Constant and the Temperature of the CMB
9
作者 Tomofumi Miyashita 《Journal of Modern Physics》 CAS 2023年第4期432-444,共13页
In previous papers, we proposed an empirical equation for the fine-structure constant. Using this equation, we proposed a refined version of our own former empirical equations about the electromagnetic force and gravi... In previous papers, we proposed an empirical equation for the fine-structure constant. Using this equation, we proposed a refined version of our own former empirical equations about the electromagnetic force and gravity in terms of the temperature of the cosmic microwave background. The calculated values of the temperature of the cosmic microwave background (T<sub>c</sub>) and the gravitational constant (G) were 2.726312 K and 6.673778 × 10<sup>-11</sup> m<sup>3</sup>⋅kg<sup>-1</sup>⋅ s<sup>-2</sup>, respectively. Then, for the values of the factors 9/2 and π in our equations, we used 4.488519503 and 3.132011447, respectively. However, we could not provide a theoretical explanation for the necessity of these empirical equations. In this paper, using the redefinition method for the UNIT, we show the necessity for our empirical equations. 展开更多
关键词 gravitational Constant Temperature of the cosmic Microwave Background
在线阅读 下载PDF
Imprints of an early matter-dominated era arising from dark matter dilution mechanism on cosmic string dynamics and gravitational wave signatures
10
作者 Shi-Qi Ling Zhao-Huan Yu 《Chinese Physics C》 2025年第10期345-360,共16页
We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves.Specifically,we examine the case where this era origin... We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves.Specifically,we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model.By numerically solving the Boltzmann equations governing the energy densities of the relevant components,we meticulously analyze the modifications to the cosmological scale factor,the number density of cosmic string loops,and the gravitational wave spectrum.Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum,providing distinct and testable signatures for future ground-based interferometer experiments. 展开更多
关键词 gravitational waves cosmic strings early matter-dominated era dark matter dilution mechanism early universe
原文传递
Inflation, Cosmic Perturbations and Non-Gaussianities
11
作者 王一 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第7期109-166,共58页
We review the theory of inflationary perturbations. Perturbations at both linear and nonlinear orders are reviewed. We also review a variety of inflation models, emphasizing their signatures on cosmic perturbations.
关键词 INFLATION cosmic perturbation gravitationAL wave NON-GAUSSIANITY
原文传递
New Discovery on Planck Units and Physical Dimension in Cosmic Continuum Theory
12
作者 Xijia Wang 《Journal of Modern Physics》 2018年第14期2391-2401,共11页
In 1899, Max Planck integrated the Planck constant h with the gravitational constant G and the speed of light c, discovered a set of physical constants, and created Planck Units System. Since 20th century, the develop... In 1899, Max Planck integrated the Planck constant h with the gravitational constant G and the speed of light c, discovered a set of physical constants, and created Planck Units System. Since 20th century, the development of physics made the gravitational constant, the speed of light, and the Planck constant the most important fundamental constants of physics representing classical theory, relativity, and quantum theory, respectively. Now, the Planck Units have been given new physical meanings, revealing the mysteries of many physical boundaries. However, more than 100 years have passed, Planck Units System not only failed to get rid of the incompatibility between the basic theories of physics, but also cannot surpass the limitations of existing physics theories. In Cosmic Continuum Theory, physical dimensions can be transformed under the principle of equivalence. Planck units system not only integrates into the axiom system of Cosmic Continuum Theory, but also establishes a benchmark for the unity of physical dimensions. The introduction of the abstract physical dimensions “JX” and “XJ” makes the physical dimension of existence quantity and dimension quantity unified respectively. 展开更多
关键词 cosmic Continuum Axiomatic PHYSICS Fundamental CONSTANTS of PHYSICS gravitational REDSHIFT PLANCK UNITS Dimensional Analysis
在线阅读 下载PDF
Cosmic microwave background constraints on the tensor-to-scalar ratio
13
作者 King Lau Jia-Yu Tang Ming-Chung Chu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第6期635-647,共13页
One of the main goals of modern cosmic microwave background (CMB) missions is to measure the tensor-to-scalar ratio r accurately to constrain inflation models. Due to ignorance about the reionization history Xe (z... One of the main goals of modern cosmic microwave background (CMB) missions is to measure the tensor-to-scalar ratio r accurately to constrain inflation models. Due to ignorance about the reionization history Xe (z), this analysis is usu- ally done by assuming an instantaneous reionization Xe (z) which, however, can bias the best-fit value of r. Moreover, due to the strong mixing of B-mode and E-mode polarizations in cut-sky measurements, multiplying the sky coverage fraction fsky by the full-sky likelihood would not give satisfactory results. In this work, we forecast constraints on r for the Planck mission taking into account the general reionization scenario and cut-sky effects. Our results show that by applying an N-point interpo- lation analysis to the reionization history, the bias induced by the assumption of in- stantaneous reionization is removed and the value of r is constrained within 5% error level, if the true value of r is greater than about 0.1. 展开更多
关键词 cosmology: cosmic microwave background -- cosmology: cosmologicalparameters -- cosmology: early universe -- gravitational waves
在线阅读 下载PDF
Quantum Model of Gravity Unifies Relativistic Effects, Describes Inflation/Expansion Transition, Matches CMB Data
14
作者 Jody A. Geiger 《Journal of High Energy Physics, Gravitation and Cosmology》 2018年第4期655-694,共40页
Presenting a unified model of motion and gravity has proved difficult as current approaches to quantum and classical physics are incompatible. Using measurement quantization—a model that demonstrates the physical sig... Presenting a unified model of motion and gravity has proved difficult as current approaches to quantum and classical physics are incompatible. Using measurement quantization—a model that demonstrates the physical significance of Planck’s units of length, mass, and time—measure is expressed as counts of the fundamental units establishing a common framework for describing quantum and cosmological phenomena with expressions that are defined throughout the entire physical domain. Beginning with the Pythagorean Theorem, we demonstrate an understanding of measure with respect to static and moving references. The model is extended to include the measure of mass thus completing a single approach for describing the contraction and dilation of measure. With this new approach, relativistic effects are now described as properties of quantized finite units of measure. In support of the model, several descriptions of phenomena are resolved that match our most precise data such as the measure of dark energy, universal expansion, mass distribution, and the age of the Cosmic Microwave Background. 展开更多
关键词 Relativity Measurement Distortion Length Contraction Time DILATION QUANTUM gravitY gravitational Constant PLANCK Units DARK Energy DARK Matter cosmic Microwave Background Space-Time Curvature
在线阅读 下载PDF
Cosmic Applications of Relative Energy between Quarks in Nucleons
15
作者 F. C. Hoh 《Journal of Modern Physics》 2019年第14期1645-1658,共14页
By taking into account the relative energy between the diquark and the quark in nucleons, the gravitational singularity in a black hole created from a collapsing neutron star can be removed;compatibility with quantum ... By taking into account the relative energy between the diquark and the quark in nucleons, the gravitational singularity in a black hole created from a collapsing neutron star can be removed;compatibility with quantum mechanics is restored. This black hole becomes a “black” neutron star. The negative relative energy identified as dark matter in the previous paper can account for the galaxy rotation curve. The positive relative energy identified as dark energy in the previous paper can explain the accelerating expansion of the universe. A possible scenario for cosmic ray generation is given. 展开更多
关键词 gravitational Singularity Relative Energy BETWEEN QUARKS Scalar Strong Interaction HADRON Theory “Weightless” NEUTRON Black NEUTRON Star Galaxy Rotation Curve Accelerating Expansion of Universe cosmic Ray
在线阅读 下载PDF
A Quantum Space Model of Cosmic Evolution: Dark Energy and the Cyclic Universe
16
作者 Carlos A. Melendres 《Journal of Modern Physics》 CAS 2022年第11期1305-1313,共9页
We present a Quantum Space Model (QSM) of cosmic evolution based on the theory that space consists of energy quanta from which our universe came about. We used the Friedmann equations to trace its history and predict ... We present a Quantum Space Model (QSM) of cosmic evolution based on the theory that space consists of energy quanta from which our universe came about. We used the Friedmann equations to trace its history and predict its ultimate fate. Results provide further support to our recent proposal that the accelerating expansion of the universe is due to a scalar space field which has become known as Dark Energy. In our model, the universe started from high energy space quanta which were triggered by quantum fluctuations that caused the Big Bang. It then expanded and cooled undergoing phase transitions to radiation, fundamental particles, and matter. Matter agglomerated and grew into stars, galaxies, etc. and was eventually consolidated by gravity into Black Holes, which finally ended in a Big Crunch in a state of deep freeze inside the Black hole at 1.380 trillion years. Fluctuations, quantum tunneling, or some other mechanisms caused a new Bang to start another cycle in its life. Our results are in good agreement with the theoretical predictions of a cyclic universe by Steinhardt and his associates, and by Penrose. Space and energy are equivalent as embodied in the Planck energy equation. They give rise to the two principal long range forces in the universe: the gravitational force and the space force. The latter may be the fifth force in the universe. The two forces could provide the clockwork mechanism operating our cyclic universe. If the Law of Conservation of Energy is universal, then the cosmos is eternal. 展开更多
关键词 Quantum Space Model Spaceons Dark Energy gravitational Waves cosmic Evolution Expansion of the Universe Black Holes Big Bang Big Crunch Cyclic Universe
在线阅读 下载PDF
Uncompensated Centrifugal Flow about Accelerated Cosmic Expansion
17
作者 Luis Alberto Pé rez Pé rez 《World Journal of Mechanics》 2021年第4期83-93,共11页
Currently, we are under the perception of a <em>visible universe</em> which has an <em>accelerated expansion</em>, because repeated evidences obtained by several technics since the well known o... Currently, we are under the perception of a <em>visible universe</em> which has an <em>accelerated expansion</em>, because repeated evidences obtained by several technics since the well known observations performed by Edwin Powell Hubble. The world scientific community was astonished by these observations, and since then until today, countless calculations have been made that only leave the hypothesis of the existence of an unknown <em>cosmic entity</em> that has the particularity of repelling matter from each other when it is sufficiently separated by huge amounts of that entity, which was called as “<em>dark energy</em>”. This “<em>dark energy</em>” is a completely unknown thing, and it is understood by some researchers as the convenient hypothesis, because it is which emerges from deep calculations and observations. Bearing in mind that we already know about all cosmic objects and systems are in rotation, both locally and not so locally, and that everything is full and endowed with intrinsic and extrinsic angular momentum, it seems logical to think that <em>rotational dynamics</em> must also apply to the more extensive, and that if locally (and not so locally) we perceive and infer rotating objects everywhere, then they must also exist globally. So, starting from the idea that rotation is omnipresent, at every level of sizes;from the invisibly small to the invisibly large, I thought that it is really wise to cover it through <em>rotation dynamics</em>, or that in the worst case, we cannot ignore the fact of the omnipresent rotation in any entity to infer. And this is the main reason for the resolution and the motivation of the birth of the publication of this study. Based on this seemingly simple idea, these results and conclusions of this study was reached: following a formal logic and evidence of the accelerated unfolding of the cosmic fabric, another hypothesis is proposed as an alternative to the existence of the “<em>dark energy</em>”: The <em>intensities of centrifugal acceleration fluxes</em> exceed the <em>intensities of gravitational fluxes</em>, which are not sufficient to compensate for the <em>centrifugal flux</em>, which is why baryonic and exotic matter, energy, space and time are extended, in geometric progression with respect to our apparent time. So, this unfolding of the cosmic fabric might not be caused by a “<em>dark energy</em>”, but by <em>centrifugal fields of rotational-orbital domains</em>. Besides all the above, this publication has a double purpose, because it is also intended to cover another matter;these deep attentions to the Rotational Dynamics also derive in another solution or hypothesis regarding the formed mystery after observing the incoherent too high velocity of matter in the far latitudes in spiral galaxies: The hypothesis of the existence of the so-called “<em>dark matter</em>” arises from the observation that, in spiral galaxies, all that matter which is located beyond a critical distance from the galactic rotation axis, travels too fast, while the calculations illustrate an insufficient intensity of <em>gravitational acceleration flux</em> to explain that speed and to retain all that matter while maintaining the orbital distance. However, the concept I present here, is that, in a spiral galaxy, all those matter which is positioned farthest from the <em>main rotation axis</em>, is effectively lost in space as time goes by, or what is the same, the <em>intensity of the centrifugal acceleration field</em> is not compensated by that of the <em>gravitational field</em>, and the destiny of every spiral galaxy is a more or less homogeneous and compact disk-shaped galaxy. As a basic NOTE to be taken into account;in the present article we intend to show the radical, meticulous and delicate relation that exists in the considerations of the <u>classic concept of “<em>isolated system of particles</em>”</u>, with the <u>degrees of the consistencies of the connections between all those “<em>particles</em>”</u>, whether they are inter-material bonds, or, in a relativistic scope, bonds between the same cosmic fabric. And this is so, because the idea of “<em>isolated</em>” falls directly and precisely on the criterion that we put to the <u>degree of consistency of each connection between each “<em>part</em>” or “<em>particle</em>”</u> that integrates the presumed and inferred concept of “<em>isolated system</em>” with respect to the rest of systems or universe. 展开更多
关键词 Fields Theory Inertial Fields Rotational Dynamics Angular Momentum Orbitation Macroscopic Bodies Mechanics Dark Energy Dark Matter Centrifugal Action Intermolecular Bonds cosmic Fabric Inter-Astral Ligatures gravitational Field Strength
在线阅读 下载PDF
Algorithms for Empirical Equations in Terms of the Cosmic Microwave Background Temperature
18
作者 Tomofumi Miyashita 《Journal of Modern Physics》 2024年第10期1567-1585,共19页
Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among... Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (Tc) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10−11 m3∙kg−1∙s−2, respectively. Every equation can be explained numerically in terms of the Compton length of an electron (λe), the Compton length of a proton (λp) and α. Furthermore, every equation can also be explained in terms of the Avogadro number and the number of electrons at 1 C. We show that every equation can be described in terms of the Planck constant. Then, the ratio of the gravitational force to the electric force can be uniquely determined with the assumption of minimum mass. In this report, we describe the algorithms used to explain these equations in detail. Thus, there are no dimension mismatch problems. 展开更多
关键词 Temperature of the cosmic Microwave Background Minimum Mass The Ratio of gravitational Force to Electric Force Dimension Analysis Redefinition Method Fine Structure Constant
在线阅读 下载PDF
利用引力波探测宇宙膨胀历史
19
作者 朱良贵 陈弦 《物理》 北大核心 2025年第7期461-470,共10页
宇宙膨胀历史的信息反映在银河系外天体的距离和红移的关系中。引力波探测允许观测者直接测量引力波源的光度距离,而以电磁波为信使的传统天文观测可以测量引力波源的红移信息,两者结合可以用于探测宇宙的膨胀历史。2017年,LIGO和Virgo... 宇宙膨胀历史的信息反映在银河系外天体的距离和红移的关系中。引力波探测允许观测者直接测量引力波源的光度距离,而以电磁波为信使的传统天文观测可以测量引力波源的红移信息,两者结合可以用于探测宇宙的膨胀历史。2017年,LIGO和Virgo利用双中子星并合引力波事件GW170817的多信使联合观测,首次实现了利用引力波对宇宙膨胀速度的测量。利用引力波探测宇宙膨胀历史不依赖于传统电磁观测的测距方式,可以作为解决当前宇宙学危机的极具潜力的手段。文章将介绍利用引力波探测宇宙膨胀历史的基本原理、目前的探测结果和未来的预期表现,以及待解决的问题。 展开更多
关键词 引力波探测 标准汽笛 哈勃常数 暗能量状态方程 宇宙膨胀
原文传递
Gravitational waves from cosmic strings associated with pseudo-Nambu-Goldstone dark matter
20
作者 邱泽宇 余钊焕 《Chinese Physics C》 SCIE CAS CSCD 2023年第8期149-161,共13页
We study stochastic gravitational waves from cosmic strings generated in an ultraviolet-complete model for pseudo-Nambu-Goldstone dark matter with a hidden U(1)gauge symmetry.The dark matter candidate in this model ca... We study stochastic gravitational waves from cosmic strings generated in an ultraviolet-complete model for pseudo-Nambu-Goldstone dark matter with a hidden U(1)gauge symmetry.The dark matter candidate in this model can naturally evade direct detection bounds and easily satisfy other phenomenological constraints.The bound on the dark matter lifetime implies an ultraviolet scale higher than 10^(9)GeV.The spontaneous U(1)symmetry breaking at such a high scale would induce cosmic strings with high tension,resulting in a stochastic gravitational wave background with a high energy density.We investigate the constraints from current gravitational wave experiments as well as the future sensitivity.We find that most viable parameter points can be well studied in future gravitational waveexperiments. 展开更多
关键词 dark matter gravitational waves cosmic strings beyond the standard model
原文传递
上一页 1 2 4 下一页 到第
使用帮助 返回顶部