Using the Klauder enhanced quantization as a way to specify the cosmological constant as a baseline for the mass of a graviton, we eventually come up and then we will go to the Starobinsky potential as a replacement f...Using the Klauder enhanced quantization as a way to specify the cosmological constant as a baseline for the mass of a graviton, we eventually come up and then we will go to the Starobinsky potential as a replacement for the term N used in Equation (3) and Equation (4). From there we will read in a way to describe conditions allowing for where the cosmological constant may be set. The idea also is to describe a regime of space-time where the initial perturbation/start to inflation actually occurred, as is alluded to in the final part of the document.展开更多
We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation...We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, while using Karen Freeze’s criteria as to the breakup of primordial black holes to give radiation era contributions to GW generation. The GW generation will be when there is sufficient early universe density so as to break apart Relic Black holes of the order of Planck mass (10<sup>15</sup> grams) which is about when the mass of relic black holes is created, 10<sup>-27</sup> or so seconds after expansion starts. Needles to state a key result will be in the initial potential V calculated, in terms of other input variables.展开更多
It is shown that the non-equilibrium electrically neutral and relativistically invariant vacuum-like state with the negative energy density and positive pressure may exist at the non-zero temperature in the system of ...It is shown that the non-equilibrium electrically neutral and relativistically invariant vacuum-like state with the negative energy density and positive pressure may exist at the non-zero temperature in the system of spinor particles, antiparticles, and random electromagnetic field generated by particle-particle, particle-antiparticle, and antiparticle-antiparticle transitions. At the temperature of the order of 10 <sup>-5</sup> K, the energy density of its state corresponds to the dark energy density in absolute magnitude. The cosmological constant for such material medium turns out to be negative.展开更多
In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum sta...In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum states over the other possible types of vacuum states”? This document tries to answer how a preferred vacuum state could be produced, and by what sort of process. We construct a di quark condensate leading to a cosmological constant in line with known physical observations. We use a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. This permits criteria for initiation of graviton production from a domain wall formed after a transition to a chaotic inflationary potential. It also permits investigation of if or not axion wall contributions to inflation are necessary. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to rescale and reset initial conditions for the chaotic inflationary potential. Then the Randall-Sundrum brane world effective potential delineates the end of the dominant role of di quarks, and the beginning of inflation. And perhaps answers Freeman Dysons contention that Graviton production is unlikely given present astrophysical constraints upon detector systems. We end this with a description in the last appendix entry, Appendix VI, as to why, given the emphasis upon di quarks, as to the usefulness of using times before Planck time interval as to modeling our physical system and its importance as to emergent field structures used for cosmological modeling.展开更多
In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field equations.We compute the quasino...In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field equations.We compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational perturbations.By varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter BH surrounded by quintessence(RN-dSQ).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ are different only when the charge parameter q is varied.Therefore,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime separately.Another interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates slowly.We also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.展开更多
This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous ...This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous and anisotropic Bianchi type Ⅰ space-time have been obtained. The solutions of the Einstein's field equations are obtained by considering(i) the power law relation between Hubble parameter H and scale factor R and(ii) scale factor of the form R =-1/t + t^2, t > 1. The assumptions lead to constant and variable deceleration parameter respectively. The physical and dynamical behaviors of the models have been discussed with the help of graphical representations. Also we have discussed the stability and physical acceptability of solutions for solution type-Ⅰ and solution type-Ⅱ.展开更多
For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We h...For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We here offer a solution to the cosmological constant problem by extending the Einstein-Friedmann equations by one additional time dimension. Solving these equations, we find that the Universe is flat on a global scale and that the cosmological constant lies between 10<sup>-90</sup> m<sup>-2</sup> and 10<sup>-51</sup> m<sup>-2</sup> which is in range observed by experiments. It also proposes a mean to explain the Planck length and to mitigate the singularity at the Big Bang.展开更多
Einstein’s field equation is a highly general equation consisting of sixteen equations. However, the equation itself provides limited information about the universe unless it is solved with different boundary conditi...Einstein’s field equation is a highly general equation consisting of sixteen equations. However, the equation itself provides limited information about the universe unless it is solved with different boundary conditions. Multiple solutions have been utilized to predict cosmic scales, and among them, the Friedmann-Lemaître-Robertson-Walker solution that is the back-bone of the development into today standard model of modern cosmology: The Λ-CDM model. However, this is naturally not the only solution to Einstein’s field equation. We will investigate the extremal solutions of the Reissner-Nordström, Kerr, and Kerr-Newman metrics. Interestingly, in their extremal cases, these solutions yield identical predictions for horizons and escape velocity. These solutions can be employed to formulate a new cosmological model that resembles the Friedmann equation. However, a significant distinction arises in the extremal universe solution, which does not necessitate the ad hoc insertion of the cosmological constant;instead, it emerges naturally from the derivation itself. To the best of our knowledge, all other solutions relying on the cosmological constant do so by initially ad hoc inserting it into Einstein’s field equation. This clarification unveils the true nature of the cosmological constant, suggesting that it serves as a correction factor for strong gravitational fields, accurately predicting real-world cosmological phenomena only within the extremal solutions of the discussed metrics, all derived strictly from Einstein’s field equation.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
The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed ...The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed to present in ICRANET Zeldovich 4, 2020. We present a history of the evolution of the cosmological constant “issue” starting with its introduction by Einstein for a static universe, which did not work out because his static universe solution to the Ricci Scalar problem, and GR was and is UNSTABLE. Another model of the cosmological constant has a radius of the Universe specified which is proportional to one over the square root of the cosmological constant, whereas our idea is to use the matching of two spacetime first integrals, for isolating a nonperturbative cosmological constant solution right at the surface of the start of expansion of the universe, <i>i.e.</i> a phenomenological solution to the cosmological constant involves scaling of a radius of the PRESENT universe. Our presented idea is to instead solve the Cosmological constant at the surface of the initial space-time bubble, using the initially derived time step, delta t, as input for the Cosmological constant. As it is, the Zeldovich 4 Section I was in was for Dark Energy, so in solving the initial value of the Cosmological constant, I am giving backing to one of the models of DE as to why the Universe reaccelerates one billion years ago. We conclude as to a reference to a multiverse generalization of Penrose Cyclic Conformal Cosmology as input into the initial nonsingular space-time bubble.展开更多
Instant preheating as given in terms of window where adiabaticity is violated is a completely inefficient form of particle production if we use Padmandabhan scalar potentials. This necessitates using a very different ...Instant preheating as given in terms of window where adiabaticity is violated is a completely inefficient form of particle production if we use Padmandabhan scalar potentials. This necessitates using a very different mechanism for early universe gravition production as an example which is to break up the initial “mass” formed about 10<sup>60</sup> times Planck mass into graviton emitting 10<sup>5</sup> gram sized micro black holes. The mechanism is to assume that we have a different condition than the usual adiabaticity idea which is connected with reheating of the universe. Hence, we will be looking at an earlier primordial black hole generation for generation of gravitons.展开更多
A framework to estimate the mass of the universe from quarks is presented, taking spacetime into account. This is a link currently missing in our understanding of physics/science. The focus on mass-energy balance is a...A framework to estimate the mass of the universe from quarks is presented, taking spacetime into account. This is a link currently missing in our understanding of physics/science. The focus on mass-energy balance is aimed at finding a solution to the Cosmological Constant (CC) problem by attempting to quantize space-time and linking the vacuum energy density at the beginning of the universe and the current energy density. The CC problem is the famous disagreement of approximately 120 orders of magnitude between the theoretical energy density at the Planck scale and the indirectly measured cosmological energy density. Same framework is also used to determine the mass of the proton and neutron from first principles. The only input is the up quark (u-quark) mass, or precisely, the 1st generation quarks. The method assumes that the u-quark is twice as massive as the down-quark (d-quark). The gap equation is the starting point, introduced in its simplest form. The main idea is to assume that all the particles and fields in the unit universe are divided into quarks and everything else. Everything else means all fields and forces present in the universe. It is assumed that everything else can be “quark-quantized”;that is, assume that they can be quantized into similar sizeable u-quarks and/or it’s associated interactions and relations. The result is surprisingly almost as measured and known values. The proton structure and mass composition are also analysed, showing that it likely has more than 3 quarks and more than 3 valence quarks. It is also possible to estimate the percentage of dark matter, dark energy, ordinary matter, and anti-matter. Finally, the cosmological constant problem or puzzle is resolved by connecting the vacuum energy density of Quantum Field Theory (5.1E+96 kg/m<sup>3</sup>) and the energy density of General Relativity (1.04E−26 kg/m<sup>3</sup>). Upon maturation, this framework can serve as a bridging platform between Quantum Field Theory and General Relativity. Other aspects of natures’ field theories can be successfully ported to the platform. It also increases the chances of solving some of the unanswered questions in physics.展开更多
This paper integrates a quantum conception of the Planck epoch early universe with FSC model formulae and the holographic principle, to offer a reasonable explanation and solution of the cosmological constant problem....This paper integrates a quantum conception of the Planck epoch early universe with FSC model formulae and the holographic principle, to offer a reasonable explanation and solution of the cosmological constant problem. Such a solution does not appear to be achievable in cosmological models which do not integrate black hole formulae with quantum formulae such as the Stephan-Boltzmann law. As demonstrated herein, assuming a constant value of Lambda over the great span of cosmic time appears to have been a mistake. It appears that Einstein’s assumption of a constant, in terms of vacuum energy density, was not only a mistake for a statically-balanced universe, but also a mistake for a dynamically-expanding universe.展开更多
We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation...We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, using the Rosen and Israelit model of a nonsingular universe. In doing so we are in addition to obtaining a wavelength 10<sup>30</sup> times greater than Planck’s length so we can calculate DE, may be able to with the help of the Rosen and Israelit model have a first approximation as to the arrow of time, and a universe with massive gravity. We have left the particulars of the nonsingular starting point undefined but state that the Rosen and Israelit model postulates initial temperatures of 10<sup>-180</sup> Kelvin and also a value of about Planck temperature, at 10<sup>-3</sup> centimeters radii value which may satisfy initial conditions asked by t’Hooft for describing an arrow of time. A key assumption is that the DE is formed at 10<sup>-3</sup> cm, after an expansion of 10<sup>30</sup> times in radii, from the Planck length radius nonsingular starting point. The given starting point for DE in this set of assumptions is where there is a change in the cosmic acceleration, to a zero value, according to Rosen and Israel, with time <i>t</i> = 1.31 times 10<sup>-42</sup> seconds. That may be where we may specify a potential magnitude, <i>V</i>, which has ties into inflaton physics. The particulars of the model from Rosen and Israelit allow a solution to be found, without discussion of where that nonsingular starting point came from, a point the author found in need of drastic remedies and fixes.展开更多
By means of the dimensional analysis a spherically simmetric universe with a mass M = c<sup>3</sup>/(2HG) and radius equal to c/H is considered, where H is the Hubble constant, c the speed of light and G t...By means of the dimensional analysis a spherically simmetric universe with a mass M = c<sup>3</sup>/(2HG) and radius equal to c/H is considered, where H is the Hubble constant, c the speed of light and G the Newton gravitational constant. The density corresponding to this mass is equal to the critical density ρ<sub>cr </sub>= 3H<sup>2</sup>/(8πG). This universe evolves according to a Bondi-Gold-Hoyle scenario, with continuous creation of matter at a rate such to maintain, during the expansion, the density always critical density. Using the Margolus-Levitin theorem and the Landauer’s principle, an entropy is associated with this universe, obtaining a formula having the same structure as the Bekenstein-Hawking formula of the entropy of a black hole. Furthermore, a time-dependent cosmological constant Λ, function of the Hubble constant and the speed of light, is proposed.展开更多
For a system with a Hamiltonian constraint,we demonstrate that its dynamics is invariant under different choices of the lapse function,regardless of whether the Hamiltonian incorporates quantum corrections.Applying th...For a system with a Hamiltonian constraint,we demonstrate that its dynamics is invariant under different choices of the lapse function,regardless of whether the Hamiltonian incorporates quantum corrections.Applying this observation to the interior of black-to-white holes,we analyze its dynamics with different choices of the lapse function.The results explicitly show that the leading-order expansion of both metrics proposed by Rovelli et al.(Class.Quant.Grav.35,225003(2018);Class.Quant.Grav.35,215010(2018))and Ashtekar et al.(Phys.Rev.Lett.121,241301(2018);Phys.Rev.D 98,126003(2018))exhibit identical behavior near the transition surface.Therefore,in this sense the black-to-white hole model proposed by Rovelli et al.,(Class.Quant.Grav.35,225003(2018);Class.Quant.Grav.35,215010(2018))may be interpreted as a coarse-grained version of the solution within the framework of loop quantum gravity.The black-to-white hole solutions with exact symmetry between the black hole and white hole regions are constructed by appropriately fixing the quantum parameters in the effective theory of loop quantum gravity.This approach circumvents the issue of amplification of mass,which could arise from a mass difference between the black hole and white hole,and provides a way to link the solutions obtained by minisuperspace quantization to those in the covariant approach.Finally,the black-to-white hole solutions with a cosmological constant are constructed.The numerical solutions for the interior of the black-to-white hole with a cosmological constant are obtained,and their symmetric behavior is also discussed.展开更多
Traditionally,the cosmological constant has been viewed as dark energy that mimics matter with negative energy.Given that matter with negative energy provides a repulsive force,which fundamentally differs from typical...Traditionally,the cosmological constant has been viewed as dark energy that mimics matter with negative energy.Given that matter with negative energy provides a repulsive force,which fundamentally differs from typical gravitational forces,it has been believed that the cosmological constant effectively contributes a repulsive force.However,it is important to note that the concept of gravitational force is valid only within the framework of Newtonian dynamics.In this study,we demonstrate that the traditional understanding of the gravitational force contributed by the cosmological constant is not entirely correct.Our approach involves investigating the Newtonian limit of the Einstein equation with a cosmological constant.The subtleties involved in this analysis are discussed in detail.Interestingly,we find that the effect of the cosmological constant on Newtonian gravity is an attractive force rather than a repulsive one for ordinary matter.As expected,this corrective force is negligibly small.However,our findings may offer a way to distinguish between dark energy and the cosmological constant,as one contributes a repulsive force while the other contributes an attractive force.展开更多
Based on the Veneziano ghost theory of QCD, we predict the cosmological constant A, which is related to energy density of cosmological vacuum by A = 3-8tG/pA. In the Veneziano ghost theory, the vacuum energy density P...Based on the Veneziano ghost theory of QCD, we predict the cosmological constant A, which is related to energy density of cosmological vacuum by A = 3-8tG/pA. In the Veneziano ghost theory, the vacuum energy density PA is expressed by absolute value of the product of quark vacuum condensate and quark current mass： PA = 2g/Hclmq（OI ： qq ： 10）l- We calculate the quark local vacuum condensates （01 ： qq ： 10） by solving Dyson Schwinger Equations for a fully dressed confining quark propagator S/（p） with an effective gluon propagator G^b（q）. The quark current mass mq is predicted by use of chiral perturbation theory. Our theoretical result of A, with the resulting （01 ： qq ： ]0} = -（235 MeV）3 and light quark current mass rnq = 3.29 6.15 MeV, is in a good agreement with the observable of the A =10-52 m-2 used widely in a great amount of literatures. Keywords cosmological constant A, Veneziano sate, quantum chromodynamics （QCD） ghost theory of QCD, local quark vacuum conden-展开更多
To solve the cosmological constant fine tuning problem,we investigate an(n+1)-dimensional generalized Randall-Sundrum brane world scenario with two(n−1)-branes instead of two 3-branes.Adopting an anisotropic metric an...To solve the cosmological constant fine tuning problem,we investigate an(n+1)-dimensional generalized Randall-Sundrum brane world scenario with two(n−1)-branes instead of two 3-branes.Adopting an anisotropic metric ansatz,we obtain the positive effective cosmological constantΩeff of order 10−124 and only require a solution≃50−80.Meanwhile,both the visible and hidden branes are stable because their tensions are positive.Therefore,the fine tuning problem can be solved quite well.Furthermore,the Hubble parameter H1(z)as a function of redshift z is in good agreement with the cosmic chronometers dataset.The evolution of the universe naturally shifts from deceleration to acceleration.This suggests that the evolution of the universe is intrinsically an extra-dimensional phenomenon.It can be regarded as a dynamic model of dark energy that is driven by the evolution of the extra dimensions on the brane.展开更多
In this paper, a new class of solutions of the vacuum Einstein＇s field equa- tions with cosmological constant is obtained. This class of solutions possesses the naked physical singularity. The norm of the Riemann cur...In this paper, a new class of solutions of the vacuum Einstein＇s field equa- tions with cosmological constant is obtained. This class of solutions possesses the naked physical singularity. The norm of the Riemann curvature tensor of this class of solutions takes infinity at some points and the solutions do not have any event horizon around the singularity.展开更多
文摘Using the Klauder enhanced quantization as a way to specify the cosmological constant as a baseline for the mass of a graviton, we eventually come up and then we will go to the Starobinsky potential as a replacement for the term N used in Equation (3) and Equation (4). From there we will read in a way to describe conditions allowing for where the cosmological constant may be set. The idea also is to describe a regime of space-time where the initial perturbation/start to inflation actually occurred, as is alluded to in the final part of the document.
文摘We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, while using Karen Freeze’s criteria as to the breakup of primordial black holes to give radiation era contributions to GW generation. The GW generation will be when there is sufficient early universe density so as to break apart Relic Black holes of the order of Planck mass (10<sup>15</sup> grams) which is about when the mass of relic black holes is created, 10<sup>-27</sup> or so seconds after expansion starts. Needles to state a key result will be in the initial potential V calculated, in terms of other input variables.
文摘It is shown that the non-equilibrium electrically neutral and relativistically invariant vacuum-like state with the negative energy density and positive pressure may exist at the non-zero temperature in the system of spinor particles, antiparticles, and random electromagnetic field generated by particle-particle, particle-antiparticle, and antiparticle-antiparticle transitions. At the temperature of the order of 10 <sup>-5</sup> K, the energy density of its state corresponds to the dark energy density in absolute magnitude. The cosmological constant for such material medium turns out to be negative.
文摘In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum states over the other possible types of vacuum states”? This document tries to answer how a preferred vacuum state could be produced, and by what sort of process. We construct a di quark condensate leading to a cosmological constant in line with known physical observations. We use a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. This permits criteria for initiation of graviton production from a domain wall formed after a transition to a chaotic inflationary potential. It also permits investigation of if or not axion wall contributions to inflation are necessary. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to rescale and reset initial conditions for the chaotic inflationary potential. Then the Randall-Sundrum brane world effective potential delineates the end of the dominant role of di quarks, and the beginning of inflation. And perhaps answers Freeman Dysons contention that Graviton production is unlikely given present astrophysical constraints upon detector systems. We end this with a description in the last appendix entry, Appendix VI, as to why, given the emphasis upon di quarks, as to the usefulness of using times before Planck time interval as to modeling our physical system and its importance as to emergent field structures used for cosmological modeling.
基金funded by the Guizhou Provincial Science and Technology Project(Guizhou Scientific Foundation-ZK[2022]General 491)the National Natural Science Foundation of China(Grant No.12265007).
文摘In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field equations.We compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational perturbations.By varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter BH surrounded by quintessence(RN-dSQ).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ are different only when the charge parameter q is varied.Therefore,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime separately.Another interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates slowly.We also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.
文摘This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous and anisotropic Bianchi type Ⅰ space-time have been obtained. The solutions of the Einstein's field equations are obtained by considering(i) the power law relation between Hubble parameter H and scale factor R and(ii) scale factor of the form R =-1/t + t^2, t > 1. The assumptions lead to constant and variable deceleration parameter respectively. The physical and dynamical behaviors of the models have been discussed with the help of graphical representations. Also we have discussed the stability and physical acceptability of solutions for solution type-Ⅰ and solution type-Ⅱ.
文摘For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We here offer a solution to the cosmological constant problem by extending the Einstein-Friedmann equations by one additional time dimension. Solving these equations, we find that the Universe is flat on a global scale and that the cosmological constant lies between 10<sup>-90</sup> m<sup>-2</sup> and 10<sup>-51</sup> m<sup>-2</sup> which is in range observed by experiments. It also proposes a mean to explain the Planck length and to mitigate the singularity at the Big Bang.
文摘Einstein’s field equation is a highly general equation consisting of sixteen equations. However, the equation itself provides limited information about the universe unless it is solved with different boundary conditions. Multiple solutions have been utilized to predict cosmic scales, and among them, the Friedmann-Lemaître-Robertson-Walker solution that is the back-bone of the development into today standard model of modern cosmology: The Λ-CDM model. However, this is naturally not the only solution to Einstein’s field equation. We will investigate the extremal solutions of the Reissner-Nordström, Kerr, and Kerr-Newman metrics. Interestingly, in their extremal cases, these solutions yield identical predictions for horizons and escape velocity. These solutions can be employed to formulate a new cosmological model that resembles the Friedmann equation. However, a significant distinction arises in the extremal universe solution, which does not necessitate the ad hoc insertion of the cosmological constant;instead, it emerges naturally from the derivation itself. To the best of our knowledge, all other solutions relying on the cosmological constant do so by initially ad hoc inserting it into Einstein’s field equation. This clarification unveils the true nature of the cosmological constant, suggesting that it serves as a correction factor for strong gravitational fields, accurately predicting real-world cosmological phenomena only within the extremal solutions of the discussed metrics, all derived strictly from Einstein’s field equation.
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The following is a rendition of what was presented by the author, September 11, 2020 in the DE section of that conference. The topics, while not original, are in strict fidelity with the topics the author was allowed to present in ICRANET Zeldovich 4, 2020. We present a history of the evolution of the cosmological constant “issue” starting with its introduction by Einstein for a static universe, which did not work out because his static universe solution to the Ricci Scalar problem, and GR was and is UNSTABLE. Another model of the cosmological constant has a radius of the Universe specified which is proportional to one over the square root of the cosmological constant, whereas our idea is to use the matching of two spacetime first integrals, for isolating a nonperturbative cosmological constant solution right at the surface of the start of expansion of the universe, <i>i.e.</i> a phenomenological solution to the cosmological constant involves scaling of a radius of the PRESENT universe. Our presented idea is to instead solve the Cosmological constant at the surface of the initial space-time bubble, using the initially derived time step, delta t, as input for the Cosmological constant. As it is, the Zeldovich 4 Section I was in was for Dark Energy, so in solving the initial value of the Cosmological constant, I am giving backing to one of the models of DE as to why the Universe reaccelerates one billion years ago. We conclude as to a reference to a multiverse generalization of Penrose Cyclic Conformal Cosmology as input into the initial nonsingular space-time bubble.
文摘Instant preheating as given in terms of window where adiabaticity is violated is a completely inefficient form of particle production if we use Padmandabhan scalar potentials. This necessitates using a very different mechanism for early universe gravition production as an example which is to break up the initial “mass” formed about 10<sup>60</sup> times Planck mass into graviton emitting 10<sup>5</sup> gram sized micro black holes. The mechanism is to assume that we have a different condition than the usual adiabaticity idea which is connected with reheating of the universe. Hence, we will be looking at an earlier primordial black hole generation for generation of gravitons.
文摘A framework to estimate the mass of the universe from quarks is presented, taking spacetime into account. This is a link currently missing in our understanding of physics/science. The focus on mass-energy balance is aimed at finding a solution to the Cosmological Constant (CC) problem by attempting to quantize space-time and linking the vacuum energy density at the beginning of the universe and the current energy density. The CC problem is the famous disagreement of approximately 120 orders of magnitude between the theoretical energy density at the Planck scale and the indirectly measured cosmological energy density. Same framework is also used to determine the mass of the proton and neutron from first principles. The only input is the up quark (u-quark) mass, or precisely, the 1st generation quarks. The method assumes that the u-quark is twice as massive as the down-quark (d-quark). The gap equation is the starting point, introduced in its simplest form. The main idea is to assume that all the particles and fields in the unit universe are divided into quarks and everything else. Everything else means all fields and forces present in the universe. It is assumed that everything else can be “quark-quantized”;that is, assume that they can be quantized into similar sizeable u-quarks and/or it’s associated interactions and relations. The result is surprisingly almost as measured and known values. The proton structure and mass composition are also analysed, showing that it likely has more than 3 quarks and more than 3 valence quarks. It is also possible to estimate the percentage of dark matter, dark energy, ordinary matter, and anti-matter. Finally, the cosmological constant problem or puzzle is resolved by connecting the vacuum energy density of Quantum Field Theory (5.1E+96 kg/m<sup>3</sup>) and the energy density of General Relativity (1.04E−26 kg/m<sup>3</sup>). Upon maturation, this framework can serve as a bridging platform between Quantum Field Theory and General Relativity. Other aspects of natures’ field theories can be successfully ported to the platform. It also increases the chances of solving some of the unanswered questions in physics.
文摘This paper integrates a quantum conception of the Planck epoch early universe with FSC model formulae and the holographic principle, to offer a reasonable explanation and solution of the cosmological constant problem. Such a solution does not appear to be achievable in cosmological models which do not integrate black hole formulae with quantum formulae such as the Stephan-Boltzmann law. As demonstrated herein, assuming a constant value of Lambda over the great span of cosmic time appears to have been a mistake. It appears that Einstein’s assumption of a constant, in terms of vacuum energy density, was not only a mistake for a statically-balanced universe, but also a mistake for a dynamically-expanding universe.
文摘We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, given zero-point energy calculation with an unexpected “length” added to the “width” of a graviton wave just prior to specifying the creation of “gravitons”, using the Rosen and Israelit model of a nonsingular universe. In doing so we are in addition to obtaining a wavelength 10<sup>30</sup> times greater than Planck’s length so we can calculate DE, may be able to with the help of the Rosen and Israelit model have a first approximation as to the arrow of time, and a universe with massive gravity. We have left the particulars of the nonsingular starting point undefined but state that the Rosen and Israelit model postulates initial temperatures of 10<sup>-180</sup> Kelvin and also a value of about Planck temperature, at 10<sup>-3</sup> centimeters radii value which may satisfy initial conditions asked by t’Hooft for describing an arrow of time. A key assumption is that the DE is formed at 10<sup>-3</sup> cm, after an expansion of 10<sup>30</sup> times in radii, from the Planck length radius nonsingular starting point. The given starting point for DE in this set of assumptions is where there is a change in the cosmic acceleration, to a zero value, according to Rosen and Israel, with time <i>t</i> = 1.31 times 10<sup>-42</sup> seconds. That may be where we may specify a potential magnitude, <i>V</i>, which has ties into inflaton physics. The particulars of the model from Rosen and Israelit allow a solution to be found, without discussion of where that nonsingular starting point came from, a point the author found in need of drastic remedies and fixes.
文摘By means of the dimensional analysis a spherically simmetric universe with a mass M = c<sup>3</sup>/(2HG) and radius equal to c/H is considered, where H is the Hubble constant, c the speed of light and G the Newton gravitational constant. The density corresponding to this mass is equal to the critical density ρ<sub>cr </sub>= 3H<sup>2</sup>/(8πG). This universe evolves according to a Bondi-Gold-Hoyle scenario, with continuous creation of matter at a rate such to maintain, during the expansion, the density always critical density. Using the Margolus-Levitin theorem and the Landauer’s principle, an entropy is associated with this universe, obtaining a formula having the same structure as the Bekenstein-Hawking formula of the entropy of a black hole. Furthermore, a time-dependent cosmological constant Λ, function of the Hubble constant and the speed of light, is proposed.
基金supported by the National Natural Science Foundation of China(Grant Nos.12035016,12275275,12105231,and 12275350)the Beijing Natural Science Foundation(Grant No.1222031)+1 种基金the Innovative Projects of Science and Technology(Grant No.E2545BU210)at IHEPthe Natural Science Foundation of Sichuan Province(Grant No.2024ZYD0075)。
文摘For a system with a Hamiltonian constraint,we demonstrate that its dynamics is invariant under different choices of the lapse function,regardless of whether the Hamiltonian incorporates quantum corrections.Applying this observation to the interior of black-to-white holes,we analyze its dynamics with different choices of the lapse function.The results explicitly show that the leading-order expansion of both metrics proposed by Rovelli et al.(Class.Quant.Grav.35,225003(2018);Class.Quant.Grav.35,215010(2018))and Ashtekar et al.(Phys.Rev.Lett.121,241301(2018);Phys.Rev.D 98,126003(2018))exhibit identical behavior near the transition surface.Therefore,in this sense the black-to-white hole model proposed by Rovelli et al.,(Class.Quant.Grav.35,225003(2018);Class.Quant.Grav.35,215010(2018))may be interpreted as a coarse-grained version of the solution within the framework of loop quantum gravity.The black-to-white hole solutions with exact symmetry between the black hole and white hole regions are constructed by appropriately fixing the quantum parameters in the effective theory of loop quantum gravity.This approach circumvents the issue of amplification of mass,which could arise from a mass difference between the black hole and white hole,and provides a way to link the solutions obtained by minisuperspace quantization to those in the covariant approach.Finally,the black-to-white hole solutions with a cosmological constant are constructed.The numerical solutions for the interior of the black-to-white hole with a cosmological constant are obtained,and their symmetric behavior is also discussed.
基金Supported by the National Natural Science Foundation of China(12275350)the Natural Science Foundation of Hunan Province,China(2023JJ30179)。
文摘Traditionally,the cosmological constant has been viewed as dark energy that mimics matter with negative energy.Given that matter with negative energy provides a repulsive force,which fundamentally differs from typical gravitational forces,it has been believed that the cosmological constant effectively contributes a repulsive force.However,it is important to note that the concept of gravitational force is valid only within the framework of Newtonian dynamics.In this study,we demonstrate that the traditional understanding of the gravitational force contributed by the cosmological constant is not entirely correct.Our approach involves investigating the Newtonian limit of the Einstein equation with a cosmological constant.The subtleties involved in this analysis are discussed in detail.Interestingly,we find that the effect of the cosmological constant on Newtonian gravity is an attractive force rather than a repulsive one for ordinary matter.As expected,this corrective force is negligibly small.However,our findings may offer a way to distinguish between dark energy and the cosmological constant,as one contributes a repulsive force while the other contributes an attractive force.
文摘Based on the Veneziano ghost theory of QCD, we predict the cosmological constant A, which is related to energy density of cosmological vacuum by A = 3-8tG/pA. In the Veneziano ghost theory, the vacuum energy density PA is expressed by absolute value of the product of quark vacuum condensate and quark current mass： PA = 2g/Hclmq（OI ： qq ： 10）l- We calculate the quark local vacuum condensates （01 ： qq ： 10） by solving Dyson Schwinger Equations for a fully dressed confining quark propagator S/（p） with an effective gluon propagator G^b（q）. The quark current mass mq is predicted by use of chiral perturbation theory. Our theoretical result of A, with the resulting （01 ： qq ： ]0} = -（235 MeV）3 and light quark current mass rnq = 3.29 6.15 MeV, is in a good agreement with the observable of the A =10-52 m-2 used widely in a great amount of literatures. Keywords cosmological constant A, Veneziano sate, quantum chromodynamics （QCD） ghost theory of QCD, local quark vacuum conden-
基金Supported by State Key Program of National Natural Science Foundation of China(11535005)the National Natural Science Foundation of China(11647087),the Natural Science Foundation of Yangzhou Polytechnic Institute(201917)the Natural Science Foundation of Changzhou Institute of Technology(YN1509)。
文摘To solve the cosmological constant fine tuning problem,we investigate an(n+1)-dimensional generalized Randall-Sundrum brane world scenario with two(n−1)-branes instead of two 3-branes.Adopting an anisotropic metric ansatz,we obtain the positive effective cosmological constantΩeff of order 10−124 and only require a solution≃50−80.Meanwhile,both the visible and hidden branes are stable because their tensions are positive.Therefore,the fine tuning problem can be solved quite well.Furthermore,the Hubble parameter H1(z)as a function of redshift z is in good agreement with the cosmic chronometers dataset.The evolution of the universe naturally shifts from deceleration to acceleration.This suggests that the evolution of the universe is intrinsically an extra-dimensional phenomenon.It can be regarded as a dynamic model of dark energy that is driven by the evolution of the extra dimensions on the brane.
基金supported by National Natural Science Foundation of China(Grant No.11101085)Natural Science Foundation of Fujian Province(Grant No.2015J0101)
文摘In this paper, a new class of solutions of the vacuum Einstein＇s field equa- tions with cosmological constant is obtained. This class of solutions possesses the naked physical singularity. The norm of the Riemann curvature tensor of this class of solutions takes infinity at some points and the solutions do not have any event horizon around the singularity.
