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200 papers

Theories of emergent gravity have established a deep connection between entropy and the geometry of spacetime by looking at the latter through a thermodynamic lens. In this framework, the macroscopic properties of gravity arise in a…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Valeria Rossi , Sergio Luigi Cacciatori , Alessandro Pesci

We use the idea of the symmetry between the spacetime coordinates x^\mu and the energy-momentum p^\mu in quantum theory to construct a momentum space quantum gravity geometry with a metric s_{\mu\nu} and a curvature P^\lambda_{\mu\nu\rho}.…

General Relativity and Quantum Cosmology · Physics 2016-03-08 J. W. Moffat

In general relativity, the description of spacetime relies on idealised rods and clocks, which identify a reference frame. In any concrete scenario, reference frames are associated to physical systems, which are ultimately quantum in…

Quantum Physics · Physics 2021-07-28 Flaminia Giacomini

The relativistic conception of space and time is challenged by the quantum nature of physical observables. It has been known for a long time that Poincar\'e symmetry of field theory can be extended to the larger conformal symmetry. We use…

Quantum Physics · Physics 2013-02-27 Marc-Thierry Jaekel , Serge Reynaud

Compactification of the 5-dimensional Kaluza-Klein space-time geometry is considered. The space-time geometry is supposed to be discrete, uniform and isotropic. It is shown, that consideration of the space-time geometry as a physical…

General Physics · Physics 2011-05-13 Yuri A. Rylov

We investigate the Weyl space-time extension of general relativity (GR) for studying the FLRW cosmology through focusing and defocusing of the geodesic congruences. We have derived the equations of evolution for expansion, shear and…

General Relativity and Quantum Cosmology · Physics 2011-12-06 Radouane Gannouji , Hemwati Nandan , Naresh Dadhich

Recently, in a series of papers, we established the existence and found a general solution for the simultaneously rotating and twisting locally rotationally symmetric spacetimes in general relativity, which can model inhomogeneous and…

General Relativity and Quantum Cosmology · Physics 2017-09-25 Sayuri Singh , Amare Abebe , Rituparno Goswami , Sunil D. Maharaj

In the field theories with twistor structure particles can be identified with (spacially bounded) caustics of null geodesic congruences defined by the twistor field. As a realization, we consider the ``algebrodynamical'' approach based on…

High Energy Physics - Theory · Physics 2007-05-23 Vladimir V. Kassandrov

The advanced state of cosmological observations constantly tests the alternative theories of gravity that originate from Einstein's theory. However, this is not restricted to modifications to general relativity. In this sense, we work in…

General Relativity and Quantum Cosmology · Physics 2020-11-10 Mohsen Fathi , Mona Kariminezhad , Marco Olivares , J. R. Villanueva

Emergent gravity is based on the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as U(1) gauge theory is defined on a…

High Energy Physics - Theory · Physics 2013-06-10 Sunggeun Lee , Raju Roychowdhury , Hyun Seok Yang

With the aid of a Fermi-Walker chart associated with an orthonormal frame attached to a time-like curve in spacetime, a discussion is given of relativistic balance laws that may be used to construct models of massive particles with spin,…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Robin W. Tucker

We present the explicit solution to the geodesic equations in a warped de Sitter space-time proposed by Randall-Sundrum. We find that a test particle moves in the bulk and is not restricted on a 3-brane (to be taken as our universe). On the…

General Relativity and Quantum Cosmology · Physics 2011-08-04 Jose A. Magpantay

Development of the contemporary theory of physical phenomena in the microcosm is considered to be a result of development of Einstein's ideas on a possibility of the event space modification and on a possibility of stochastic (Brownian)…

General Physics · Physics 2007-05-23 Yuri A. Rylov

The lack of a well-established solution for the gravitational energy problem might be one of the reasons why a clear road to quantum gravity does not exist. In this paper, the gravitational energy is studied in detail with the help of the…

General Relativity and Quantum Cosmology · Physics 2023-08-25 J. B. Formiga , João Duarte

Since the advent of quantum mechanics we have mainly been concerned with its predictions from the perspective of an external observer. This is in strong contrast to the theory of general relativity, where the physics is governed by the…

Quantum Physics · Physics 2014-11-17 Dries Sels , Michiel Wouters

We use a result of Hawking and Gilkey to define a Euclidean path integral of gravity and matter which has the special property of being independent of the choice of basis in the space of fields. This property allows the path integral to…

General Relativity and Quantum Cosmology · Physics 2023-08-04 Marcus Reitz , Barbara Šoda , Achim Kempf

Recently Ho$\breve{r}$ava proposed a non-relativistic renormalisable theory of gravitation. When restricted to satisfy the condition of detailed balance, this theory is intimately related to topologically massive gravity in three…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Juhua Chen , Yongjiu Wang

The main aim of this article is to investigate a spacetime of quasi-constant sectional curvature. At first, the existence of such a spacetime is established by several examples. We have shown that a spacetime of quasi-constant sectional…

Differential Geometry · Mathematics 2024-02-27 Uday Chand De , Krishnendu De , Fusun Ozen Zengin , Sezgin Altay Demirbag

In previous works, we showed that both time and space can emerge from entanglement within a globally constrained quantum Universe, with no background coordinates. By extending the Page and Wootters quantum time formalism to include both…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Tommaso Favalli

In the event symmetric approach to quantum gravity it is assumed that the fundamental laws of physics must be invariant under exchange of any two space-time events. The fact that this symmetry if obviously not observed is attributed to the…

High Energy Physics - Theory · Physics 2007-05-23 P. E. Gibbs