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Ashtekar-Kodama Gravity as a Classical and Quantum Extension of Loop Quantum Gravity
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作者 Jan Helm 《Journal of Modern Physics》 2024年第6期864-937,共74页
This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and i... This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams. 展开更多
关键词 quantum gravity loop quantum gravity General Relativity Gravitational Wave Gauge Field Theory Graviton Hamiltonian Constraint Gaussian Constraint Diffeomorphism Constraint
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Loop Quantum Gravity Harmonic Oscillator
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作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2023年第9期1287-1303,共17页
Attempts to unify Gravity Theory and Quantum Field Theory (QFT) under Loop Quantum Gravity Theory (LQG), are diverse;a dividing line between classical and quantum is sought with Schrödinger cat-state experiments.... Attempts to unify Gravity Theory and Quantum Field Theory (QFT) under Loop Quantum Gravity Theory (LQG), are diverse;a dividing line between classical and quantum is sought with Schrödinger cat-state experiments. A Primordial Field Theory-based alternative is presented, and a gravity-based harmonic oscillator developed. With quantum theory applied at micro-scales and gravity theory at meso- and macro-scales, this scale-gap contributes to the conceptual problems associated with Loop Quantum Gravity. Primordial field theory, spanning all scales, is used to conceptually stretch key ideas across this gap. An LQG interpretation of the wave function associated with the oscillator is explained. 展开更多
关键词 quantum loop gravity Spacetime Ontology Energy-Time Ontology Harmonic Oscillator MESO-SCALE Cat States Gravitational Wave Function
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Counting the Microstates at the Black Hole Horizon and the Immirzi Parameter of Loop Quantum Gravity
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作者 M. Sadiq 《Journal of Applied Mathematics and Physics》 2020年第10期2055-2062,共8页
Motivated by Bekenstein’s original thought that led him to his famous area-entropy formula for a black hole and by our recent study regarding the black hole dynamics, we identify the appropriate microscopic degrees o... Motivated by Bekenstein’s original thought that led him to his famous area-entropy formula for a black hole and by our recent study regarding the black hole dynamics, we identify the appropriate microscopic degrees of freedom in loop quantum gravity that are responsible for the black hole entropy. We achieve consistent results by taking the <em>j</em> = 1/2 edges as dominant and by subjecting these edges to experience quantum fluctuations at the horizon. This also leads to a modification of the value of the Immirzi parameter in the <em>SU</em>(2) framework. 展开更多
关键词 Immirzi Parameter Spin Networks quantum gravity loop quantum gravity Isotropic Oscillator SU(2) Quasinormal Modes Black Hole
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Entropy of black holes with arbitrary shapes in loop quantum gravity 被引量:1
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作者 ShuPeng Song HaiDa Li +1 位作者 YongGe Ma Cong Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2021年第12期76-83,共8页
The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity. The idea of characterizing the shape of a horizon by a sequence of... The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity. The idea of characterizing the shape of a horizon by a sequence of local areas is successfully applied in the scheme to calculate the entropy by the S O(1, 1) BF boundary theory matching loop quantum gravity in the bulk. The generating function for calculating the microscopical degrees of freedom of a given isolated horizon is obtained. Numerical computations of small black holes indicate a new entropy formula containing the quantum correction related to the partition of the horizon. Further evidence shows that, for a given horizon area, the entropy decreases as a black hole deviates from the spherically symmetric one,and the entropy formula is also well suitable for big black holes. 展开更多
关键词 isolated horizon ENTROPY loop quantum gravity
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Ontology of Quantum Gravity
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作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2023年第11期1392-1408,共17页
A theory of Quantum Gravity based on Primordial Field Theory is applied to a fundamental particle, the neutron. The result is compared to the current quantum description of the neutron bouncing in a gravitational fiel... A theory of Quantum Gravity based on Primordial Field Theory is applied to a fundamental particle, the neutron. The result is compared to the current quantum description of the neutron bouncing in a gravitational field. Our quantum gravity theory yields results in agreement with the Q-bounce experimental data, but ontologically different from quantum mechanics. The differences are summarized and imply that this experiment on a fundamental particle has the potential to radically alter the ontology of field theory. 展开更多
关键词 loop quantum gravity ONTOLOGY Neutron Bounce Primordial Field Theory Q-Bounce Neutron Flux
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Entropy of nonrotating isolated horizons in Lovelock theory from loop quantum gravity
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作者 王晶波 黄超光 李林 《Chinese Physics C》 SCIE CAS CSCD 2016年第8期33-36,共4页
In this paper, the BF theory method is applied to the nonrotating isolated horizons in Lovelock theory. The final entropy matches the Wald entropy formula for this theory. We also confirm the conclusion obtained by Bo... In this paper, the BF theory method is applied to the nonrotating isolated horizons in Lovelock theory. The final entropy matches the Wald entropy formula for this theory. We also confirm the conclusion obtained by Bodendorfer et al. that the entropy is related to the flux operator rather than the area operator in general diffeomorphic-invariant theory. 展开更多
关键词 loop quantum gravity entropy of isolated horizons Lovelock theory
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A Number Theoretic Analysis of the Enthalpy, Enthalpy Energy Density, Thermodynamic Volume, and the Equation of State of a Modified White Hole, and the Implications to the Quantum Vacuum Spacetime, Matter Creation and the Planck Frequency
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作者 Michele Nardelli Amos S. Kubeka Alizera Amani 《Journal of Modern Physics》 2024年第1期1-50,共50页
In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Th... In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Theory, Ramanujan Recurring Numbers, DN Constant and String Theory, that enable us to extract the quantum geometrical properties of these thermodynamic equations and the implication to the quantum vacuum spacetime geometry of our early universe as they act as the constraints to the nature of quantum gravity of the universe. 展开更多
关键词 Number Theory Ramanujan Recurring Numbers DN Constant String Theory loop quantum gravity Matter Creation Enthalpy Energy Density Thermodynamic Volume ENTHALPY
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On the improved dynamics approach in loop quantum black holes
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作者 Hongchao Zhang Wen-Cong Gan +1 位作者 Yungui Gong Anzhong Wang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第3期138-143,共6页
In this paper,we consider the B?hmer–Vandersloot(BV)model of loop quantum black holes obtained from the improved dynamics approach.We adopt the Saini–Singh gauge,in which it was found analytically that the BV spacet... In this paper,we consider the B?hmer–Vandersloot(BV)model of loop quantum black holes obtained from the improved dynamics approach.We adopt the Saini–Singh gauge,in which it was found analytically that the BV spacetime is geodesically complete.We show that black/white hole horizons do not exist in this geodesically complete spacetime.Instead,there exists only an infinite number of transition surfaces,which always separate trapped regions from anti-trapped ones.Comments on the improved dynamics approach adopted in other models of loop quantum black holes are also given. 展开更多
关键词 loop quantum gravity black hole dynamics approach
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Quantum Mechanics Hypothesis of Solar System Structure: Quantum de Broglie Wavelength, LQG Similitude and Slow Bang Theory (SB)
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作者 Jean Perron 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2022年第3期835-852,共18页
This idea of quantifying the energy of bodies orbiting the Sun is not new. We have identified that quantization applies well if we use the true quantum number associated with the true energy state of rotating bodies. ... This idea of quantifying the energy of bodies orbiting the Sun is not new. We have identified that quantization applies well if we use the true quantum number associated with the true energy state of rotating bodies. This quantum number is very high for the main bodies or planets (10<sup>~70 to 76</sup>). However, since quantum energy levels E are very high and ΔE very low we observe that bodies can in practice occupy all orbits. Thus, the current observed stable positions of the bodies are the results of the quantization and the sum of the effects of other perturbative phenomena. To find a quantum state starting with n = 1, we expressed the true integer quantum numbers as a function of that of the planet Mercury and we find an excellent correlation. However, the search for a correlation of prediction of the average orbital radius of bodies using the simple integer number n = 1, 2, 3, 4, 5, 6, 7, … is not excellent for bodies beyond the planet Pluto. Indeed, several trans-Neptunian bodies have similar integer quantum numbers, which poses a problem in the sequence of integer numbers beyond 10. Moreover, it appears that the trans-Neptunian bodies seem to be grouped for many of them according to relatively well-defined bands. The study made it possible to question the de Broglie wavelength of bodies (10<sup>~-58 to -65</sup> m). Indeed, with the hypothesis of Planck quantities that would apply to the scale of the universe, it is difficult to conceive that de Broglie wavelengths are less than the Planck length l<sub>p</sub>. This led to an expression of the modified de Broglie wavelength λ<sub>m</sub> that predicts an asymptotic lower limit value equal to πl<sub>p</sub>. This modified de Broglie wavelength makes it possible to obtain a better correlation for the prediction of the average orbital radius of bodies. Finally, this modified wavelength of de Broglie made it possible to put into perspective the concept of the quantification of space with the idea of the minimum wavelength associated with photon’s energies during the generation of the energy of the universe according to a model already presented in this review. This modified de Broglie wavelength also makes it possible to imagine that the quantification of the volume of space involves the geometry of the sphere and the cube. 展开更多
关键词 Solar System de Broglie Wavelength quantum Mechanics loop quantum gravity LQG
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The Black Hole Spray and the Cosmic Web
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作者 Rami Rom 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第2期519-523,共5页
We propose that the trapped antimatter in super massive black hole ergoregions acts as detonators that triggers black hole to white hole transitions creating huge BHs explosions that generate BH spray that acts as see... We propose that the trapped antimatter in super massive black hole ergoregions acts as detonators that triggers black hole to white hole transitions creating huge BHs explosions that generate BH spray that acts as seeds for new galaxies creation. We propose that by mapping and simulating the cosmic web structure, it may be possible to learn if the universe was created in a single big bang that started a single chain of BH explosions mini-creation event cycles, or alternatively, the BH explosions mini-creation event cycles are uncorrelated spacelike events, and the universe had no single primeval atom beginning. . 展开更多
关键词 Big Bang Quasi Steady State Cosmology (QSSC) Black Hole (BH) Supper Massive Black Hole (SMBH) White Hole (WH) Ergoregion Dark Matter (DM) Cosmic Web loop quantum gravity (LQG)
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Nonexistence of quantum black and white hole horizons in an improved dynamic approach
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作者 Wen-Cong Gan Xiao-Mei Kuang +3 位作者 Zhen-Hao Yang Yungui Gong Anzhong Wang Bin Wang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第8期56-73,共18页
In this paper,we study the quantum geometric effects near the locations where classical black hole horizons used to appear in Einstein's classical theory,within the framework of an improved dynamic approach,in whi... In this paper,we study the quantum geometric effects near the locations where classical black hole horizons used to appear in Einstein's classical theory,within the framework of an improved dynamic approach,in which the internal region of a black hole is modeled by the Kantowski-Sachs(KS)spacetime and the two polymerization parameters are functions of the phase space variables.Our detailed analysis shows that the effects are so strong that black and white hole horizons of the effective quantum theory do not exist at all and instead are replaced by transition surfaces,across which the metric coefficients and their inverses are smooth and remain finite,as are the corresponding curvatures,including the Kretschmann scalar.These surfaces always separate trapped regions from anti-trapped regions.The number of such surfaces is infinite,so the corresponding KS spacetimes become geodesically complete,and no black and white hole-like structures exist in this scheme. 展开更多
关键词 canonical quantization loop quantum gravity quantum aspects of black holes
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Immirzi parameter and quasinormal modes in four and higher spacetime dimensions
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作者 Xiang-Dong Zhang 《Frontiers of physics》 SCIE CSCD 2016年第4期133-136,共4页
There is a one-parameter quantization ambiguity in loop quantum gravity, which is called the Immirzi parameter. In this paper, we fix this free parameter by considering the quasinormal mode spectrum of black holes in ... There is a one-parameter quantization ambiguity in loop quantum gravity, which is called the Immirzi parameter. In this paper, we fix this free parameter by considering the quasinormal mode spectrum of black holes in four and higher spacetime dimensions. As a consequence, our result is consistent with the Bekenstein-Hawking entropy of a black hole. Moreover, we also give a possible quantum gravity explanation of the universal In 3 behavior of the quasinormal mode spectrum. 展开更多
关键词 Immirzi parameter quasinormal mode loop quantum gravity
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