From recent observational data two significant directions have been made in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data, ...From recent observational data two significant directions have been made in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data, to examine theoretical predictions from the standard inflationary ACDM which were made decades of years ago. Second, we can search for new cosmological signatures as a way to explore physics beyond the standard cosmic paradigm. In particular, a subset of early universe models admit a nonsingular bouncing solution that attempts to address the issue of the big bang singularity. These models have achieved a series of considerable developments in recent years, in particular in their perturbative frameworks, which made brand-new predictions of cosmological signatures that could be visible in current and forthcoming observations. Herein we present two representative paradigms of early universe physics. The first is the reputed new matter （or matter-ekpyrotic） bounce scenario in which the universe starts with a matter-dominated contraction phase and transitions into an ekpyrotic phase. In the setting of this paradigm, we have proposed some possible mechanisms of generating a red tilt for primordial curvature perturbations and confront the general predictions with recent cosmological observations. The second is the matter-bounce inflation scenario which can be viewed as an extension of inflationary cosmology with a matter contraction before inflation. We present a class of possible model constructions and review the implications on the current CMB experiments. Lastly a review of significant achievements of these paradigms beyond the inflationary ACDM model is made, which is expected to shed new light on the future direction of observational cosmology.展开更多
We reduplicate the Book “Dark Energy” by M. Li, X.-D. Li, and Y. Wang, zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wavefunction just prior to the entrance of “gr...We reduplicate the Book “Dark Energy” by M. Li, X.-D. Li, and Y. Wang, zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wavefunction just prior to the entrance of “gravitons” to a small region of space-time prior to a nonsingular start to the universe. We compare this to a solution which worked out using Klauder Enhanced quantization, for the same given problem. The solution of the first Cosmological Constant problem relies upon the geometry of the multiverse generalization of CCC cosmology which is explained in this paper. The second solution used involves Klauder enhanced quantization. We look at energy given by our methods and compare and contrast it with the negative energy of the Rosen model for a mini sub-universe and estimate GW frequencies.展开更多
We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as o...We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as of yet no consensus as to how, say GW or other signals from a wormhole mouth could be quantized or made to be in adherence to a procedure Weber cribbed from Feynman, in 1961. In addition, we utilize an approximation for the Hubble parameter parameterized from Temperature using Sarkar’s H ~ Temperature relations, as given in the text. Finally, after doing this, we go to the Energy as E also ~ Temperature, and from there use E (energy) as ~ signal frequency. This gives us an idea of how to estimate frequency generated at the mouth of a wormhole.展开更多
We revisit how we utilized how Weber in 1961 initiated the process of quantization of early universe fields to the issue of what was for a wormhole mouth. While the wormhole models are well understood, there is not su...We revisit how we utilized how Weber in 1961 initiated the process of quantization of early universe fields to the issue of what was for a wormhole mouth. While the wormhole models are well understood, there is not such a consensus as to how the mouth of a wormhole could generate signals. We try to develop a model for doing so and then revisit it, the Wormhole while considering a Tokamak model we used in a different publication as a way of generating GW, and Gravitons.展开更多
We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there w...We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there we first access the Rosen solution to a mini universe energy to ascertain an energy value of t, the pre-inflationary near singularity, then access what would be needed as to inject information into our universe. We then close with an argument by Narilkar as to a quantum bound on the Einstein-Hilbert action integral, so as to obtain quantum Gravity. Narlikar omits the cosmological constant. We keep it in, for our overall conclusion about the cosmological constant and its relevance to Quantum gravity.展开更多
We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as o...We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as of yet no consensus as to how, say GW or other signals from a wormhole mouth could be quantized or made to be in adherence to a procedure Weber cribbed from Feynman, in 1961. In addition, we utilize an approximation for the Hubble parameter parameterized from Temperature using Sarkar’s H ~ Temperature relations, as given in the text. We review what could be a game changer, <i>i.e.</i> magnetic black holes as brought up by Maldacena, in early 2021, at the mouth of the wormhole, and compare this with more standard black holes, at the mouth of a wormhole, while considering also the Bierman battery effect of an accreditation disk moving charges around a black hole as yet another way to have signals generated. The Maldacena article has good order of estimate approximations as to the strength of a magnetic monopole which we can use, and we also will go back to the signal processing effects which may be engendered by the Weber quantization of a wormhole to complete our model.展开更多
In the framework of a five-dimensional （5D） bounce cosmological model, a useful function f（z） is obtained by giving a concrete expression of deceleration parameter q（z） = q1 ＋q2/1＋1n（1＋z） Then using the obt...In the framework of a five-dimensional （5D） bounce cosmological model, a useful function f（z） is obtained by giving a concrete expression of deceleration parameter q（z） = q1 ＋q2/1＋1n（1＋z） Then using the obtained Hubble parameter H（z） according to the function f（z）, we constrain the accelerating universe from recent cosmic observations： the 192 ESSENCE SNe Ia and the 9 observational H（z） data. The best fitting values of transition redshift zT and current deceleration parameter q0 are given as zT =0.65-0.12^＋0.25 and q0=-0.76-0.15^＋0.15（1σ）. Furthermore, in the 5D bounce model it can be seen that the evolution of equation of state （EOS） for dark energy Wde can cross over -1 at about z = 0.23 and the current value W0de ： =-1.15 〈 -1. On the other hand, by giving a concrete expression of model-independent EOS of dark energy Wde, in the 5D bounce model we obtain the best fitting values zT = 0 .66-0.08^＋0.11 and q0=-0.69-0.10^＋0.10（1σ） from the recently observed data： the 192 ESSENCE SNe Ia, the observational H（z） data, the 3-year Wilkinson Microwave Anisotropy Probe （WMAP）, the Sloan Digital Sky Survey （SDSS） baryon acoustic peak and the x-ray gas mass fraction in clusters.展开更多
The detection of GW170817 and its electromagnetic counterpart has revealed the speed of gravitational waves coincides with the speed of light, cT= 1. Inspired by the possibility that the physics implied by GW170817 mi...The detection of GW170817 and its electromagnetic counterpart has revealed the speed of gravitational waves coincides with the speed of light, cT= 1. Inspired by the possibility that the physics implied by GW170817 might be related with that for the primordial universe, we construct the spatially ?at stable(throughout the whole evolution)nonsingular bounce models in the beyond Horndeski theory with cT= 1 and in the degenerate higher-order scalar-tensor(DHOST) theory with cT= 1, respectively. Though it constricts the space of viable models, the constraint of cT= 1 makes the procedure of building models simpler.展开更多
First, we do a Taylor series expansion of Entropy. Afterwards we define the arrow of time. After that, we define what terms we will analyze in the Taylor series expansion of entropy to help in finding initial conditio...First, we do a Taylor series expansion of Entropy. Afterwards we define the arrow of time. After that, we define what terms we will analyze in the Taylor series expansion of entropy to help in finding initial conditions which may allow for the earliest possible identification of the Arrow of Time in cosmology. Definition of the arrow of time will allow choosing different initial starting points. That is, that in the actual equations of classical GR, there is no reason to have time asymmetry after given initial conditions. Time asymmetry is built into initial conditions and we start to explore which initial conditions may assist in evaluating contributions to Entropy via an analysis of which terms in a Taylor series survive, and what their sign and contribution values are.展开更多
In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations therein.As is well-known,t...In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations therein.As is well-known,the tensor perturbations generated in the very early Universe(inflation and pre-inflation regions)can account for the primordial gravitational waves(PGWs)that are to be detected by the next generation of GW experiments.We discuss the stability condition of the tensor perturbations in the bounce inflation process and investigate in detail the evolution of the perturbation variable.The general form of the tensor power spectrum is obtained both for large as well as small scale modes.As a result,we show both kinds of modes(short or long wavelength modes),and the tensor spectrum may get a positive tilt in the parametric range where the tensor perturbation proves to be stable—this interestingly hints an enhancement of gravitational waves’amplitude in the background of the f(Q)bounce-inflation scenario.Moreover,we study the LQC-like scenario as a specific case of our model,in which,the primordial tensor power spectrum turns out to be nearly scale-invariant on both small and large scales.展开更多
Within the context of the Fermi-bounce curvaton mechanism,we analyze the one-loop radiative corrections to the four-fermion interaction,generated by the non-dynamical torsion field in the Einstein-Cartan-Holst-Sciama-...Within the context of the Fermi-bounce curvaton mechanism,we analyze the one-loop radiative corrections to the four-fermion interaction,generated by the non-dynamical torsion field in the Einstein-Cartan-Holst-Sciama-Kibble theory.We show that contributions that arise from the one-loop radiative corrections modify the energy-momentum tensor,mimicking an effective Ekpyrotic fluid contribution.Therefore,we call this effect quantum Ekpyrotic mechanism.This leads to the dynamical washing out of anisotropic contributions to the energy-momentum tensor,without introducing any new extra Ekpyrotic fluid.We discuss the stability of the bouncing mechanism and derive the renormalization group flow of the dimensional coupling constantξ,checking whether any change of its sign takes place towards the bounce.This enforces the theoretical motivations in favor of the torsion curvaton bounce cosmology as an alternative candidate to the inflation paradigm.展开更多
We in this paper study a class of mechanism of the production of the primordial magnetic field(PMF) in the non-singular bouncing cosmology, through the coupling of the electromagnetic field to gravity. We adopt an ele...We in this paper study a class of mechanism of the production of the primordial magnetic field(PMF) in the non-singular bouncing cosmology, through the coupling of the electromagnetic field to gravity. We adopt an electrodynamic model with a coupling coefficient as a function of the scale factor a, i.e., f = 1 +(a/a?)^(-n), with a? and n > 0 being constants. With analytical calculations, we find that this model can yield a blue tilted power spectrum of PMF on large scales from 1 Mpc to the Hubble length if the bounce scenario has experienced a contracting phase with an equation-of-state parameter larger than-1/3. Furthermore, in order to satisfy the constraints of observational data, the present mechanism favors the so-called ekpyrotic-bounce paradigm. The back-reaction of the energy density of PMF at the bouncing point can lead to additional theoretical constraints on the underlying bouncing paradigm.展开更多
基金supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Department of Physics at McGill
文摘From recent observational data two significant directions have been made in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data, to examine theoretical predictions from the standard inflationary ACDM which were made decades of years ago. Second, we can search for new cosmological signatures as a way to explore physics beyond the standard cosmic paradigm. In particular, a subset of early universe models admit a nonsingular bouncing solution that attempts to address the issue of the big bang singularity. These models have achieved a series of considerable developments in recent years, in particular in their perturbative frameworks, which made brand-new predictions of cosmological signatures that could be visible in current and forthcoming observations. Herein we present two representative paradigms of early universe physics. The first is the reputed new matter （or matter-ekpyrotic） bounce scenario in which the universe starts with a matter-dominated contraction phase and transitions into an ekpyrotic phase. In the setting of this paradigm, we have proposed some possible mechanisms of generating a red tilt for primordial curvature perturbations and confront the general predictions with recent cosmological observations. The second is the matter-bounce inflation scenario which can be viewed as an extension of inflationary cosmology with a matter contraction before inflation. We present a class of possible model constructions and review the implications on the current CMB experiments. Lastly a review of significant achievements of these paradigms beyond the inflationary ACDM model is made, which is expected to shed new light on the future direction of observational cosmology.
文摘We reduplicate the Book “Dark Energy” by M. Li, X.-D. Li, and Y. Wang, zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wavefunction just prior to the entrance of “gravitons” to a small region of space-time prior to a nonsingular start to the universe. We compare this to a solution which worked out using Klauder Enhanced quantization, for the same given problem. The solution of the first Cosmological Constant problem relies upon the geometry of the multiverse generalization of CCC cosmology which is explained in this paper. The second solution used involves Klauder enhanced quantization. We look at energy given by our methods and compare and contrast it with the negative energy of the Rosen model for a mini sub-universe and estimate GW frequencies.
文摘We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as of yet no consensus as to how, say GW or other signals from a wormhole mouth could be quantized or made to be in adherence to a procedure Weber cribbed from Feynman, in 1961. In addition, we utilize an approximation for the Hubble parameter parameterized from Temperature using Sarkar’s H ~ Temperature relations, as given in the text. Finally, after doing this, we go to the Energy as E also ~ Temperature, and from there use E (energy) as ~ signal frequency. This gives us an idea of how to estimate frequency generated at the mouth of a wormhole.
文摘We revisit how we utilized how Weber in 1961 initiated the process of quantization of early universe fields to the issue of what was for a wormhole mouth. While the wormhole models are well understood, there is not such a consensus as to how the mouth of a wormhole could generate signals. We try to develop a model for doing so and then revisit it, the Wormhole while considering a Tokamak model we used in a different publication as a way of generating GW, and Gravitons.
文摘We take the results where we reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation, as folded in with the Klauder methodology, as given in a prior publication. From there we first access the Rosen solution to a mini universe energy to ascertain an energy value of t, the pre-inflationary near singularity, then access what would be needed as to inject information into our universe. We then close with an argument by Narilkar as to a quantum bound on the Einstein-Hilbert action integral, so as to obtain quantum Gravity. Narlikar omits the cosmological constant. We keep it in, for our overall conclusion about the cosmological constant and its relevance to Quantum gravity.
文摘We utilize how Weber in 1961 initiated the process of quantization of early universe fields to the problem of what may be emitted at the mouth of a wormhole. While the wormhole models are well developed, there is as of yet no consensus as to how, say GW or other signals from a wormhole mouth could be quantized or made to be in adherence to a procedure Weber cribbed from Feynman, in 1961. In addition, we utilize an approximation for the Hubble parameter parameterized from Temperature using Sarkar’s H ~ Temperature relations, as given in the text. We review what could be a game changer, <i>i.e.</i> magnetic black holes as brought up by Maldacena, in early 2021, at the mouth of the wormhole, and compare this with more standard black holes, at the mouth of a wormhole, while considering also the Bierman battery effect of an accreditation disk moving charges around a black hole as yet another way to have signals generated. The Maldacena article has good order of estimate approximations as to the strength of a magnetic monopole which we can use, and we also will go back to the signal processing effects which may be engendered by the Weber quantization of a wormhole to complete our model.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10573004 and 10703001)Specialized Research Fund for the Doctoral Program of Higher Education (Grant No 2007141034)
文摘In the framework of a five-dimensional （5D） bounce cosmological model, a useful function f（z） is obtained by giving a concrete expression of deceleration parameter q（z） = q1 ＋q2/1＋1n（1＋z） Then using the obtained Hubble parameter H（z） according to the function f（z）, we constrain the accelerating universe from recent cosmic observations： the 192 ESSENCE SNe Ia and the 9 observational H（z） data. The best fitting values of transition redshift zT and current deceleration parameter q0 are given as zT =0.65-0.12^＋0.25 and q0=-0.76-0.15^＋0.15（1σ）. Furthermore, in the 5D bounce model it can be seen that the evolution of equation of state （EOS） for dark energy Wde can cross over -1 at about z = 0.23 and the current value W0de ： =-1.15 〈 -1. On the other hand, by giving a concrete expression of model-independent EOS of dark energy Wde, in the 5D bounce model we obtain the best fitting values zT = 0 .66-0.08^＋0.11 and q0=-0.69-0.10^＋0.10（1σ） from the recently observed data： the 192 ESSENCE SNe Ia, the observational H（z） data, the 3-year Wilkinson Microwave Anisotropy Probe （WMAP）, the Sloan Digital Sky Survey （SDSS） baryon acoustic peak and the x-ray gas mass fraction in clusters.
基金Supported by National Natural Science Foundation of China under Grant Nos.11575188 and 11690021
文摘The detection of GW170817 and its electromagnetic counterpart has revealed the speed of gravitational waves coincides with the speed of light, cT= 1. Inspired by the possibility that the physics implied by GW170817 might be related with that for the primordial universe, we construct the spatially ?at stable(throughout the whole evolution)nonsingular bounce models in the beyond Horndeski theory with cT= 1 and in the degenerate higher-order scalar-tensor(DHOST) theory with cT= 1, respectively. Though it constricts the space of viable models, the constraint of cT= 1 makes the procedure of building models simpler.
文摘First, we do a Taylor series expansion of Entropy. Afterwards we define the arrow of time. After that, we define what terms we will analyze in the Taylor series expansion of entropy to help in finding initial conditions which may allow for the earliest possible identification of the Arrow of Time in cosmology. Definition of the arrow of time will allow choosing different initial starting points. That is, that in the actual equations of classical GR, there is no reason to have time asymmetry after given initial conditions. Time asymmetry is built into initial conditions and we start to explore which initial conditions may assist in evaluating contributions to Entropy via an analysis of which terms in a Taylor series survive, and what their sign and contribution values are.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFC2203100)the National Natrual Science Foundation of China(Grant No.11875141)。
文摘In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations therein.As is well-known,the tensor perturbations generated in the very early Universe(inflation and pre-inflation regions)can account for the primordial gravitational waves(PGWs)that are to be detected by the next generation of GW experiments.We discuss the stability condition of the tensor perturbations in the bounce inflation process and investigate in detail the evolution of the perturbation variable.The general form of the tensor power spectrum is obtained both for large as well as small scale modes.As a result,we show both kinds of modes(short or long wavelength modes),and the tensor spectrum may get a positive tilt in the parametric range where the tensor perturbation proves to be stable—this interestingly hints an enhancement of gravitational waves’amplitude in the background of the f(Q)bounce-inflation scenario.Moreover,we study the LQC-like scenario as a specific case of our model,in which,the primordial tensor power spectrum turns out to be nearly scale-invariant on both small and large scales.
基金Supported by National Natural Science Foundation of China(11875113)。
文摘Within the context of the Fermi-bounce curvaton mechanism,we analyze the one-loop radiative corrections to the four-fermion interaction,generated by the non-dynamical torsion field in the Einstein-Cartan-Holst-Sciama-Kibble theory.We show that contributions that arise from the one-loop radiative corrections modify the energy-momentum tensor,mimicking an effective Ekpyrotic fluid contribution.Therefore,we call this effect quantum Ekpyrotic mechanism.This leads to the dynamical washing out of anisotropic contributions to the energy-momentum tensor,without introducing any new extra Ekpyrotic fluid.We discuss the stability of the bouncing mechanism and derive the renormalization group flow of the dimensional coupling constantξ,checking whether any change of its sign takes place towards the bounce.This enforces the theoretical motivations in favor of the torsion curvaton bounce cosmology as an alternative candidate to the inflation paradigm.
基金supported by the National Natural Science Foundation of China for Fostering Talents in Basic Science (Grant No. J1310021)the National Natural Science Foundation of China (Grant Nos. 11653002, 11722327, and 11421303)+1 种基金the China Academy of Space Technology (CAST) Young Elite Scientists Sponsorship Program (Grant No. 2016QNRC001)the Fundamental Research Funds for the Central Universities
文摘We in this paper study a class of mechanism of the production of the primordial magnetic field(PMF) in the non-singular bouncing cosmology, through the coupling of the electromagnetic field to gravity. We adopt an electrodynamic model with a coupling coefficient as a function of the scale factor a, i.e., f = 1 +(a/a?)^(-n), with a? and n > 0 being constants. With analytical calculations, we find that this model can yield a blue tilted power spectrum of PMF on large scales from 1 Mpc to the Hubble length if the bounce scenario has experienced a contracting phase with an equation-of-state parameter larger than-1/3. Furthermore, in order to satisfy the constraints of observational data, the present mechanism favors the so-called ekpyrotic-bounce paradigm. The back-reaction of the energy density of PMF at the bouncing point can lead to additional theoretical constraints on the underlying bouncing paradigm.
