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We calculate the quasinormal modes (QNM) frequencies of a test massless scalar field and an electromagnetic field around static black holes in $f(T)$ gravity. Focusing on quadratic $f(T)$ modifications, which is a good approximation for…

General Relativity and Quantum Cosmology · Physics 2022-10-31 Yaqi Zhao , Xin Ren , Amara Ilyas , Emmanuel N. Saridakis , Yi-Fu Cai

We show how Loop Quantum Cosmology can be derived as an effective semiclassical description of Loop Quantum Gravity. Using the tools of QRLG, a gauge fixed version of LQG, we take the coherent states of the fundamental microscopic theory…

General Relativity and Quantum Cosmology · Physics 2014-10-20 Emanuele Alesci , Francesco Cianfrani

The focus of this PhD thesis is on applications, new developments and extensions of the noncommutative gravity theory proposed by Julius Wess and his group. In part one we propose an extension of the usual symmetry reduction procedure to…

Mathematical Physics · Physics 2012-10-04 Alexander Schenkel

We develop a Gauss-Bonnet extension of Loop Quantum Cosmology, by introducing holonomy corrections in modified $F(\mathcal{G})$ theories of gravity. Within the context of our formalism, we provide a perturbative expansion in the critical…

General Relativity and Quantum Cosmology · Physics 2015-12-16 J. Haro , A. N. Makarenko , A. N. Myagky , S. D. Odintsov , V. K. Oikonomou

We consider a spacetime singularity at $t = 0$ arising in a Kasner-type metric that solves the gravitational equations modified by quantum effects of a conformal field theory (CFT). The resulting constraints can be solved efficiently when…

High Energy Physics - Theory · Physics 2026-02-13 Sergey N. Solodukhin

A systematic approach is developed in order to obtain spherically symmetric midisuperspace models that accept holonomy modifications in the presence of matter fields with local degrees of freedom. In particular, starting from the most…

General Relativity and Quantum Cosmology · Physics 2022-08-12 Asier Alonso-Bardaji , David Brizuela

We analyze the quasinormal modes (QNMs) of a recently obtained solution of a Schwarzschild black hole (BH) with corrections motivated by Loop Quantum Gravity (LQG). This spacetime is regular everywhere and presents the global structure of a…

General Relativity and Quantum Cosmology · Physics 2023-05-17 Zeus S. Moreira , Haroldo C. D. Lima Junior , Luís C. B. Crispino , Carlos A. R. Herdeiro

Loop quantum gravity introduces two characteristic modifications in the classical constraints of general relativity: the holonomy and inverse-triad corrections. In this paper, a systematic construction of anomaly-free effective constraints…

General Relativity and Quantum Cosmology · Physics 2022-08-12 Asier Alonso-Bardaji , David Brizuela

Geometric methods for constructing exact solutions of motion equations with first order $\alpha ^{\prime}$ corrections to the heterotic supergravity action implying a non-trivial Yang-Mills sector and six dimensional, 6-d, almost-K\"ahler…

High Energy Physics - Theory · Physics 2017-01-16 Sergiu I. Vacaru , Klee Irwin

Loop quantum cosmology is a tentative approach to model the universe down to the Planck era where quantum gravity settings are needed. The quantization of the universe as a dynamical space-time is inspired by Loop Quantum Gravity ideas. In…

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

Based on modifications inspired from loop quantum gravity (LQG), spherically symmetric models have recently been explored to understand the resolution of classical singularities and the fate of the spacetime beyond. While such…

General Relativity and Quantum Cosmology · Physics 2023-08-23 Kristina Giesel , Hongguang Liu , Parampreet Singh , Stefan Andreas Weigl

Off-diagonal vacuum and nonvacuum configurations in Einstein gravity can mimic physical effects of modified gravitational theories of $f(R,T,R_{\mu \nu}T^{\mu \nu})$ type. To prove this statement, exact and approximate solutions are…

General Relativity and Quantum Cosmology · Physics 2015-07-01 Emilio Elizalde , Sergiu I. Vacaru

We develop an approach to the theory of relativistic geometric flows and emergent gravity defined by entropy functionals and related statistical thermodynamics models. Nonholonomic deformations of G. Perelman's functionals and related…

General Physics · Physics 2021-01-29 Sergiu I. Vacaru , Elşen Veli Veliev , Laurenţiu Bubuianu

Nonassociative modifications of general relativity, GR, defined by star products with R-flux deformations in string gravity consist of an important subclass of modified gravity theories, MGTs. A longstanding criticism for elaborating…

High Energy Physics - Theory · Physics 2024-10-10 S. Vacaru

We discuss the construction of cosmological models within the framework of Macroscopic Gravity (MG), which is a theory that models the effects of averaging the geometry of space-time on large scales. We find new exact spatially homogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Timothy Clifton , Alan Coley , Robert van den Hoogen

Loop Quantum Gravity is a nonperturbative and background independent program for the quantization of General Relativity. Its underlying formalism has been applied successfully to the study of cosmological spacetimes, both to test the…

General Relativity and Quantum Cosmology · Physics 2021-09-13 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán

We formulate an approach to the geometry of Riemann-Cartan spaces provided with nonholonomic distributions defined by generic off-diagonal and nonsymmetric metrics inducing effective nonlinear and affine connections. Such geometries can be…

General Relativity and Quantum Cosmology · Physics 2008-12-19 Sergiu I. Vacaru

We explore the relationship between the effective dynamics in standard loop quantum cosmology (LQC) based on holonomies and triads obtained from gauge-fixing fluxes, and a modification of LQC based on holonomies and gauge-covariant fluxes…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Bao-Fei Li , Parampreet Singh

The first-order loop quantum gravity correction of the simplest, classical general-relativistic Friedmann Hamiltonian constraint, emerging from a holomorphic spinfoam cosmological model peaked on homogeneous, isotropic geometries, is…

General Relativity and Quantum Cosmology · Physics 2015-07-02 Christian Röken

The current theoretical development identified as the gravitational decoupling via Complete Geometric Deformation (CGD) method that has been introduced to explore the nonmetricity $Q$ effects in relativistic astrophysics. In the present…

General Relativity and Quantum Cosmology · Physics 2023-02-06 S. K. Maurya , Ksh. Newton Singh , Santosh V Lohakare , B. Mishra