Results 21 to 30 of about 2,756,107 (244)
Homogeneous Barotropic String Cosmology Model of Bianchi Type IV0 in General Relativity
Journal of Nano- and Electronic Physics, 2023 The homogeneous barotropic string cosmology model has been widely investigated in the context of string theory and other quantum gravity theories. It has been shown that it leads to intriguing and non-trivial predictions for the early universe, such as ...
Sunil Kumawat, Laxmi Poonia
semanticscholar +1 more source
Gauge-Invariant Perturbations at a Quantum Gravity Bounce
Universe, 2022 We study the dynamics of gauge-invariant scalar perturbations in cosmological scenarios with a modified Friedmann equation, such as quantum gravity bouncing cosmologies.
Steffen Gielen, Lisa Mickel
doaj +1 more source
Hidden Quantum Effect in General Relativity
Journal of High Energy Physics Gravitation and Cosmology, 2023 If the Planck length is chosen as the natural length scale of the Universe, the Penrose-Carter diagram associated with the classical gravitational collapse of a thin spherical shell of massless matter reveals, beyond and in agreement with the claimed non
M. Socolovsky
semanticscholar +1 more source
A Rotating Model of a Light Speed Expanding Hubble-Hawking Universe
Physical Sciences Forum, 2023 Based on light speed expansion, a modified red shift formula, a scaled Hawking’s black hole temperature formula, the super gravity of galactic baryon matter and baby Planck ball, in our recent publications we have clearly established a novel model of ...
U. V. Satya Seshavatharam +1 more
doaj +1 more source
Nonsingular bouncing cosmology in general relativity: physical analysis of the spacetime defect [PDF]
Classical and quantum gravity, 2020 In this paper, we describe physical effects occurring in the regularized Robertson–Walker spacetime which can reveal the presence of the defect. Our analysis is based on two main physical quantities: the compressive forces acting on (human) observers and
E. Battista
semanticscholar +1 more source
The Quantum Memory Matrix: A Unified Framework for the Black Hole Information Paradox. [PDF]
Entropy (Basel)We present the Quantum Memory Matrix (QMM) hypothesis, which addresses the longstanding Black Hole Information Paradox rooted in the apparent conflict between Quantum Mechanics (QM) and General Relativity (GR).
Neukart F, Brasher R, Marx E.
europepmc +2 more sources
Phantom singularities and their quantum fate: general relativity and beyond—a CANTATA COST action topic [PDF]
General Relativity and Gravitation, 2019 Cosmological observations allow the possibility that dark energy is caused by phantom fields. These fields typically lead to the occurrence of singularities in the late Universe.
Mariam Bouhmadi-L'opez +2 more
semanticscholar +1 more source
Conformal Cyclic Cosmology, gravitational entropy and quantum information
General Relativity and Gravitation, 2023 We inspect the basic ideas underlying Roger Penrose’s Conformal Cyclic Cosmology from the perspective of modern quantum information. We show that the assumed loss of degrees of freedom in black holes is not compatible with the quantum notion of entropy ...
Michał Eckstein
semanticscholar +1 more source
Higher-dimensional view on quantum cosmology [PDF]
Physical Review D, 2021 We argue that the choice of boundary condition for the wave function in quantum cosmology depends on the UV completion of general relativity. We provide an explicit example using a braneworld scenario in which a de Sitter cosmology is induced on the ...
U. Danielsson +3 more
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Cosmological initial data for numerical relativity [PDF]
Phys. Rev. D 102, 044022 (2020), 2020 We find initial data for numerical relativity simulations of inhomogeneous cosmologies. This involves treating an exceptional case of the general relativity constraint equations. We devise analytic and numerical methods to treat this exceptional case. We apply the analytic method to the standard case of cosmology with a single scalar field.
arxiv +1 more source