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Upsilon Constants and Their Usefulness in Planck Scale Quantum Cosmology
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作者 Eugene Terry Tatum 《Journal of Modern Physics》 2024年第2期167-173,共7页
This paper introduces the two Upsilon constants to the reader. Their usefulness is described with respect to acting as coupling constants between the CMB temperature and the Hubble constant. In addition, this paper su... This paper introduces the two Upsilon constants to the reader. Their usefulness is described with respect to acting as coupling constants between the CMB temperature and the Hubble constant. In addition, this paper summarizes the current state of quantum cosmology with respect to the Flat Space Cosmology (FSC) model. Although the FSC quantum cosmology formulae were published in 2018, they are only rearrangements and substitutions of the other assumptions into the original FSC Hubble temperature formula. In a real sense, this temperature formula was the first quantum cosmology formula developed since Hawking’s black hole temperature formula. A recent development in the last month proves that the FSC Hubble temperature formula can be derived from the Stephan-Boltzmann law. Thus, this Hubble temperature formula effectively unites some quantum developments with the general relativity model inherent in FSC. More progress towards unification in the near-future is expected. 展开更多
关键词 quantum cosmology Hubble Constant Planck Scale Upsilon Constant Flat Space cosmology Black Holes CMB Temperature ΛCDM cosmology quantum Gravity Unification
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Dynamical Study of a Constant Viscous Dark Energy Model in Classical and Loop Quantum Cosmology
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作者 Sara Benchikh Noureddine Mebarki Dalel Aberkane 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第5期144-148,共5页
Dynamical behaviors and stability properties of a flat space Friedmann-Robertson-Walker universe filled with pressureless dark matter and viscous dark energy are studied in the context of standard classical and loop q... Dynamical behaviors and stability properties of a flat space Friedmann-Robertson-Walker universe filled with pressureless dark matter and viscous dark energy are studied in the context of standard classical and loop quantum cosmology. Assuming that the dark energy has a constant bulk viscosity, it is found that the bulk viscosity effects influence only the quintessence model case leading to the existence of a viscous late time attractor solution of de- Sitter type, whereas the quantum geometry effects influence the phantom model case where the big rip singularity is removed. Moreover, our results of the Hubble parameter as a function of the redshift are in good agreement with the more recent data. 展开更多
关键词 of on in Dynamical Study of a Constant Viscous Dark Energy Model in Classical and Loop quantum cosmology is that for been FRW
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Viscous Modified Chaplygin Gas in Classical and Loop Quantum Cosmology
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作者 D. Aberkane N. Mebarki S. Benchikh 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第6期139-143,共5页
We investigate the cosmological model of viscous modified Chaplygin gas (VMCG) in classical and loop quantum cosmology (LQC). Firstly, we constrain its equation of state parameters in the framework of standard cos... We investigate the cosmological model of viscous modified Chaplygin gas (VMCG) in classical and loop quantum cosmology (LQC). Firstly, we constrain its equation of state parameters in the framework of standard cosmology from Union 2.1 SNe Ia data. Then, we probe the dynamical stability of this model in a universe filled with VMCG and baryonic fluid in LQC background. It is found that the model is very suitable with (χ2/d.o.f = 0.974) and gives a good prediction of the current values of the deceleration parameter q0 =∈ (-0.60, -0.57) and the effective state parameter ωeff∈ (-0.76, -0.74) that is consistent with the recent observational data. The model can also predict the time crossing when (ρDE ≈ Pmatter) at z = 0.75 and can solve the coincidence problem. In LQC background, the Big Bang singularity found in classical cosmology ceases to exist and is replaced by a bounce when the Hubble parameter vanishes at ρtot≈ρc. 展开更多
关键词 Viscous Modified Chaplygin Gas in Classical and Loop quantum cosmology
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Quantum Cosmological Tetration of Time
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作者 Angus McCoss 《Journal of High Energy Physics, Gravitation and Cosmology》 2020年第2期225-237,共13页
In an original quantum cosmology model, the scale factor evolution describing Hubble expansion is solely determined by the third tetration of time. The model exhibits early accelerating expansion, mid-time deceleratin... In an original quantum cosmology model, the scale factor evolution describing Hubble expansion is solely determined by the third tetration of time. The model exhibits early accelerating expansion, mid-time decelerating expansion, and late accelerating expansion. The substrate of reality, coined the “Graphiverse”, is a quantum-classical information processing network, represented by a learning deep generative graph. It comprises two complementary sub-graphs which are the substrates of a perceived rendering and a dark rendering of the emergent physical universe. Four temporal registers that count change (i.e. dimensions of time) are defined: system time, classical complexity time, quantum-classical correlation (or discord) time, and quantum coherence time. The cosmological scale factor evolves through a right-associative iterative exponentiation of these times. In the first (right) exponentiation, quantum-classical correlation (or discord) time is the base and its exponent is quantum coherence time. In the second (left) exponentiation, classical complexity time is the base and its exponent is the first (right) exponentiation. The four temporal registers that count change self-synchronize and equalize the four dimensions of time. The model provides a nexus for a new discussion about time and quantum gravity. 展开更多
关键词 cosmologY quantum Information quantum GRAVITY COMPLEXITY Graphiverse
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Quantum Cosmology Explains the General Galaxy-Black Hole Correlation
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作者 Paul K. Suh 《International Journal of Astronomy and Astrophysics》 2012年第2期101-112,共12页
The symmetric quantum physics of the Universe demonstrates that the massive black holes developing in the post-inflation big-bang prompt the formation of the host galaxies around them. A general correlation between th... The symmetric quantum physics of the Universe demonstrates that the massive black holes developing in the post-inflation big-bang prompt the formation of the host galaxies around them. A general correlation between the variety of galaxies and black holes develops, a specific example of which is the celebrated (but not understood) mass correlation between the host elliptical galaxies and their core black holes. The elucidations and predictions in this exposition are inclusive and far-reaching, resolving a myriad of yet unsolved problems and quandaries in the evolving Universe, among which are: how the general galaxy-black hole correlations are established;what is the role of the dark matter and energy in the formation of galaxies and stars;how the spiral galaxies with less predominant black holes are formed;how the early star forming globular cluster emerged with sparse dark matter;why some galaxy mergers give rise to the starbursts, while other mergers switch the star flourishing galaxies off into grave yards;and how could the Universe have wound up as sheets and filaments of galaxy clusters encompassing great voids. 展开更多
关键词 DARK MATTER and Energy quantum Physics of the UNIVERSE cosmologY
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A Solution to the Cosmological Constant Problem Using the Holographic Principle (A Brief Note)
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作者 Eugene Terry Tatum 《Journal of Modern Physics》 2024年第2期159-166,共8页
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
关键词 quantum cosmology Planck Scale cosmological Constant Black Holes Holographic Principle Flat Space cosmology AdS-CFT ER = EPR cosmology Model
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How the Flat Space Cosmology Model Correlates the Recombination CMB Temperature of 3000 K with a Redshift of 1100
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作者 Eugene Terry Tatum U. V. S. Seshavatharam 《Journal of Modern Physics》 2024年第2期174-178,共5页
This paper shows how the Flat Space Cosmology model correlates the recom-bination epoch CMB temperature of 3000 K with a cosmological redshift of 1100. This proof is given in support of the recent publication that the... This paper shows how the Flat Space Cosmology model correlates the recom-bination epoch CMB temperature of 3000 K with a cosmological redshift of 1100. This proof is given in support of the recent publication that the Tatum and Seshavatharam Hubble temperature formulae can be derived using the Stephan-Boltzmann dispersion law. Thus, as explained herein, the era of high precision Planck scale quantum cosmology has arrived. 展开更多
关键词 Hubble Constant Cosmic Microwave Background quantum cosmology Stephan-Boltzmann Upsilon Coupling Constant Flat Space cosmology ΛCDM cosmology
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QUANTUM COSMOLOGY WITH O_(8N+1)- SYMMETRIC COUPLING SCALAR FIELD
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作者 沈有根 《Science China Mathematics》 SCIE 1990年第11期1378-1385,共8页
Using the Hartle-Hawking method, we discuss the quantum Cosmology with O_(8N+1)^-symmetric coupling scalar field. The corresponding Wheeler-De Witt equation has been derived, and the wave function of the universe calc... Using the Hartle-Hawking method, we discuss the quantum Cosmology with O_(8N+1)^-symmetric coupling scalar field. The corresponding Wheeler-De Witt equation has been derived, and the wave function of the universe calculated. We got the material solution of the cosmic wave function in harmonic eigenstate, and the solution of space is the product of the Gauss factor and one polynomial. After analysing the wave function of the universe under the quantum effect, we found that the probability density of the universe appearing at a=0 is zero, and that the minimal radius of the ground state of the universe is on the Planck scale. The analysis of the wave function of the universe, also reveals that at the very early stage of the universe the probability density of the multl-scalar field is smaller than that of the onescalar field. 展开更多
关键词 O_(2N+1)-zymmetrie coupling scalar field quantum cosmology wave function of the universe Wheeler-De Witt equation.
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De Broglie–Bohm Interpretation of Canonical Quantum Cosmology Implies Early Stages of the Universe Dominated by Radiation
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作者 Ch’ng Han Siong Shahidan Radiman 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第12期691-694,共4页
The Einstein's genera/relativity is formulated in the Hamiltonian form for a spatia/ly Bat, isotropic and homogeneous universe. Subsequently, we perform the canonical quantization procedure to the Hamiltonian to obta... The Einstein's genera/relativity is formulated in the Hamiltonian form for a spatia/ly Bat, isotropic and homogeneous universe. Subsequently, we perform the canonical quantization procedure to the Hamiltonian to obtain the Wheeler-DeWitt equation. Solving the Wheeler-DeWitt equation and employing the de Broglie-Bohm interpretation to the wave function of the universe, we obtain a new version of spatia/ly fiat Friedmann equation for the early universe where the scale factor of the universe is taken to be sufilcientlv small. 展开更多
关键词 de Broglie-Bohm interpretation canonical quantum cosmology Friedmann equation Wheeler-DeWitt equation
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Path Integrals and Alternative Effective Dynamics in Loop Quantum Cosmology
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作者 秦立 邓果 马永革 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第2期326-332,共7页
The alternative dynamics of loop quantum cosmology is examined by the path integral formulation.We consider the spatially flat FRW models with a massless scalar field,where the alternative quantizations inherit more f... The alternative dynamics of loop quantum cosmology is examined by the path integral formulation.We consider the spatially flat FRW models with a massless scalar field,where the alternative quantizations inherit more features from full loop quantum gravity.The path integrals can be formulated in both timeless and deparameterized frameworks.It turns out that the effective Hamiltonians derived from the two different viewpoints are equivalent to each other.Moreover,the first-order modified Friedmann equations are derived and predict quantum bounces for contracting universe,which coincide with those obtained in canonical theory. 展开更多
关键词 loop quantum cosmology path integral effective Hamiltonian modified Friedmann equation
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Dynamical Horizon Entropy Bound Conjecture in Loop Quantum Cosmology
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作者 李丽仿 朱建阳 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第7期63-66,共4页
The covariant entropy bound conjecture is an important hint for the quantum gravity, with several versions available in the literature. For cosmology, Ashtekar and Wilson-Ewing ever show the consistence between the lo... The covariant entropy bound conjecture is an important hint for the quantum gravity, with several versions available in the literature. For cosmology, Ashtekar and Wilson-Ewing ever show the consistence between the loop gravity theory and one version of this conjecture. Recently, He and Zhang [J. High Energy Phys. 10 (2007) 077] proposed a version for the dynamical horizon of the universe, which validates the entropy bound conjecture for the cosmology filled with perfect fluid in the classical scenario when the universe is far away from the big bang singularity. However, their conjecture breaks down near big bang region. We examine this conjecture in the context of the loop quantum cosmology. With the example of photon gas, this conjecture is protected by the quantum geometry effects as expected. 展开更多
关键词 loop quantum gravity quantum cosmology entropy bound
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Energy conditions in the new model of loop quantum cosmology
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作者 Gaoping Long Yunlong Liu Xiangdong Zhang 《Chinese Physics C》 SCIE CAS CSCD 2021年第11期143-150,共8页
Recently,a de-Sitter epoch has been found in the new model of loop quantum cosmology,which is governed by the scalar constraint with both Euclidean and Lorentz terms.The singularity free bounce in the new LQC model an... Recently,a de-Sitter epoch has been found in the new model of loop quantum cosmology,which is governed by the scalar constraint with both Euclidean and Lorentz terms.The singularity free bounce in the new LQC model and the emergent cosmology constant strongly suggest that the effective stress-energy tensor induced by quantum corrections must violate the standard energy conditions.In this study,we perform an explicit calculation to analyze the behaviors of specific representative energy conditions,i.e.,average null,strong,and dominant energy conditions.We reveal that the average null energy condition is violated at all times,while the dominant energy condition is violated only at a period around the bounce point.The strong energy condition is violated not only at a period around the bounce point but also in the whole period from the bounce point to the classical phase corresponding to the de Sitter period.Our results will shed some light on the construction of a wormhole and time machine,which usually require exotic matter to violate energy conditions. 展开更多
关键词 energy condition loop quantum cosmology quantum gravity
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Dynamics of k-essence in loop quantum cosmology
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作者 Jiali Shi Jian-Pin Wu 《Chinese Physics C》 SCIE CAS CSCD 2021年第4期451-461,共11页
In this paper,we study the dynamics of k-essence in loop quantum cosmology(LQC).The study indicates that the loop quantum gravity(LQG)effect plays a key role only in the early epoch of the universe and is diluted in t... In this paper,we study the dynamics of k-essence in loop quantum cosmology(LQC).The study indicates that the loop quantum gravity(LQG)effect plays a key role only in the early epoch of the universe and is diluted in the later stages.The fixed points in LQC are basically consistent with those in standard Friedmann-Robertson-Walker(FRW)cosmology.For most of the attractor solutions,the stability conditions in L Q C are in agreement with those for the standard FRW universe.For some special fixed points,however,tighter constraints are imposed thanks to the LQG effect. 展开更多
关键词 K-ESSENCE loop quantum cosmology dynamics of dark energy
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Study of Tachyon Warm Intermediate and Logamediate Inflationary Universe from Loop Quantum Cosmological Perspective
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作者 Jyotirmay Das Mandal Ujjal Debnath 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第8期256-262,共7页
We have studied the tachyon intermediate and logamediate warm inflation in loop quantum cosmological background by taking the dissipative co-efficient Γ = Γ_0(where Γ_0 is a constant) in "intermediate" in... We have studied the tachyon intermediate and logamediate warm inflation in loop quantum cosmological background by taking the dissipative co-efficient Γ = Γ_0(where Γ_0 is a constant) in "intermediate" inflation and Γ = V(φ),(where V(φ) is the potential of tachyonic field) in "logamediate" inflation. We have assumed slow-roll condition to construct scalar field φ, potential V, N-folds, etc. Various slow-roll parameters have also been obtained.We have analyzed the stability of this model through graphical representations. 展开更多
关键词 tachyonic field loop quantum cosmological warm inflation
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Background Dynamics of Pre-inflationary Scenario in Brans-Dicke Loop Quantum Cosmology
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作者 Manabendra Sharma Tao Zhu Anzhong Wang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2019年第10期1205-1218,共14页
Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary av... Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary avenue to explore the pre-inflationary dynamics. Brans-Dicke(BD) loop quantum cosmology(LQC) is one of such theories whose effective background dynamics is considered in this article. Starting with a quantum bounce, we explore the pre-inflationary dynamics of a universe sourced by a scalar field with the Starobinsky potential in BD-LQC. Our study is based on the idea that though Einstein’s and Jordan’s frames are classically equivalent up to a conformal transformation in BD theory, this is no longer true after quantization. Taking the Jordan frame as the physical one we explore in detail the bouncing scenario which is followed by a phase of a slow roll inflation. The three phases of the evolution of the universe, namely, bouncing, transition from quantum bounce to classical universe, and the slow roll inflation, are noted for an initially kinetic energy dominated bounce. In addition, to be consistent with observations, we also identify the allowed phase space of initial conditions that would produce at least 60 e-folds of expansion during the slow roll inflation. 展开更多
关键词 loop quantum cosmologY BRANS-DICKE theory INFLATION quantum BOUNCE
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QUANTUM COSMOLOGY WITH SCALAR-SPINOR INTERACTION FIELD
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作者 沈有根 《Science China Mathematics》 SCIE 1989年第7期847-855,共9页
The quantum cosmology with the scalar-spinor interaction of σ model is analyzed by means of Hartle and Hawking’s method. The Wheeler-DeWitt equation is obtained and the corresponding wave function of the universe so... The quantum cosmology with the scalar-spinor interaction of σ model is analyzed by means of Hartle and Hawking’s method. The Wheeler-DeWitt equation is obtained and the corresponding wave function of the universe solved. The obtained asymptotic solution of the wave function indicates that in the σ model the contribution of the spinor part is notable when the scalar factor α is very small, and the expression of the solution is related to the initial conditions. When the scalar factor α is great, the contribution of the spinor part is not significant and has the same conduct as the scalar part. 展开更多
关键词 quantum cosmologY σ model wave function of the UNIVERSE Wheeler-DeWitt equation.
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Holographic Bound in Quantum Field Energy Density and Cosmological Constant
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作者 Paolo Castorina 《Journal of Modern Physics》 2013年第6期807-811,共5页
The cosmological constant problem is reanalyzed by imposing the limitation of the number of degrees of freedom (d.o.f.) due to entropy bounds directly in the calculation of the energy density of a field theory. It is ... The cosmological constant problem is reanalyzed by imposing the limitation of the number of degrees of freedom (d.o.f.) due to entropy bounds directly in the calculation of the energy density of a field theory. It is shown that if a quantum field theory has to be consistent with gravity and holography, i.e. with an upper limit of storing information in a given area, the ultraviolet momentum cut-off is not the Planck mass, Mp, as naively expected, but where Nu is the number of d.o.f. of the universe. The energy density evaluation turns out completely consistent with Bousso’s bound on the cosmological constant value. The scale , that in the “fat graviton” theory corresponds to the graviton size, originates by a self-similar rearrangement of the elementary d.o.f. at different scales that can be seen as an infrared-ultraviolet connection. 展开更多
关键词 cosmologICAL CONSTANT HOLOGRAPHY quantum FIELDS
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Gedanken Experiment for Energy, and Scale Factor, Based upon the Assumption of Quintessence and Idea of Quantum Bounce in Order to Isolate Admissible Frequency for Gravitational Waves in the Beginning of Cosmological Evolution
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作者 Andrew Walcott Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 2016年第1期92-97,共6页
We initially look at a non-singular universe representation of time, and of comparing a general formula of a cosmological Potential energy as given by Padmanbhan, with Weinberg’s Quintessence Potential energy. Isolat... We initially look at a non-singular universe representation of time, and of comparing a general formula of a cosmological Potential energy as given by Padmanbhan, with Weinberg’s Quintessence Potential energy. Isolating a given time component which may serve as an introduction. We then compare this to when , and seeing what the time component then allows as far as available initial energy, the scale factor a(t) and &oslash;, then finally admissible frequency, for Pre Planckian process generated Gravitational waves. 展开更多
关键词 Gedanken Experiment quantum Bounce Gravitational Waves cosmological Evolution
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How is a black hole created from nothing?
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作者 Zhongchao Wu 《中国科学技术大学学报》 CAS CSCD 北大核心 2024年第7期35-38,34,I0002,共6页
Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical... Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical singularities do not exist at the horizons of the constrained instanton.Instead,the unavoidable irregularity is presented as a nonvanishing second fundamental form elsewhere at the quantum transition 3-surface.The same arguments can be applied to charged,topological,or higher dimensional black hole cases. 展开更多
关键词 black hole creation quantum black hole quantum cosmology
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On the Cosmic Evolution of the Quantum Vacuum Using Two Variable G Models and Winterberg’s Thesis
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1134-1160,共27页
We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckion... We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum. 展开更多
关键词 Winterberg Model Planck Particles Positive and Negative Mass Planck Particles Planckions quantum Vacuum Space as a Superfluid/Supersolid Extended Models for Space cosmological Constant Higgs Field as a Composite Particle Higgs Boson Inherent Length Scale for the Vacuum Dark Energy cosmological Scaling Behavior for the quantum Vacuum Variable G Models Extended Gravity Newton’s Constant as an Order Parameter High Energy Behavior for the Vacuum
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