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Related papers: Anisotropic models in LQC with GBP polymerisation

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The paper is continuation of [6] where we have discussed some classical and quantization problems of rigid bodies of infinitesimal size moving in Riemannian spaces. Strictly speaking, we have considered oscillatory dynamical models on…

Mathematical Physics · Physics 2024-09-17 Agnieszka Martens

Singularities in general relativity such as the big bang and big crunch, and exotic singularities such as the big rip are the boundaries of the classical spacetimes. These events are marked by a divergence in the curvature invariants and…

General Relativity and Quantum Cosmology · Physics 2015-10-01 Parampreet Singh

We describe a class of exactly soluble models for gravitational collapse in spherical symmetry obtained by patching dynamical spherically symmetric exterior spacetimes with cosmological interior spacetimes. These are generalizations of the…

General Relativity and Quantum Cosmology · Physics 2013-05-29 Benjamin K. Tippett , Viqar Husain

We study the anisotropic Bianchi I and Bianchi II models in vacuum in the framework of deformed commutation relations (DCRs). Working in a parametrisation of the spatial metric by a volume and two anisotropy variables, we propose modified…

General Relativity and Quantum Cosmology · Physics 2025-10-29 Gabriele Barca , Steffen Gielen

We study the possibility of generalising the Einstein--Straus model to anisotropic settings, by considering the matching of locally cylindrically symmetric static regions to the set of $G_4$ on $S_3$ locally rotationally symmetric (LRS)…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Filipe C. Mena , Reza Tavakol , Raül Vera

We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Godel's metric and is classified as Bianchi III. This metric is an exact…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-23 W. Miranda , S. Carneiro , C. Pigozzo

We study gravitational lensing by a recently proposed black hole solution in Loop Quantum Gravity. We highlight the fact that the quantum gravity corrections to the Schwarzschild metric in this model evade the `mass suppression' effects…

General Relativity and Quantum Cosmology · Physics 2015-03-16 Satyabrata Sahu , Kinjalk Lochan , D. Narasimha

We analyze the Bianchi IX Universe in the Polymer Quantum Mechanics framework by facing both semiclassical and purely quantum effects near the cosmological singularity. We adopt Misner variables to describe the model dynamics, applying the…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Eleonora Giovannetti , Giovanni Montani

We investigate the physical and observational features of static, spherically symmetric black hole spacetimes surrounded by anisotropic fluid and embedded in a plasma environment. Motivated by recent advances in black hole imaging and…

General Relativity and Quantum Cosmology · Physics 2025-12-15 Jonibek Khasanov , Mirzabek Alloqulov , Pankaj Sheoran , Sanjar Shaymatov , Hemwati Nandan

The emergence of nontrivial symmetries for black holes minisuperspaces has been recently pointed out. These Noether symmetries possess non-null charges and hence map physical solutions to different ones. The symmetry group is isomorphic to…

General Relativity and Quantum Cosmology · Physics 2022-09-12 Francesco Sartini

We discuss the way non-perturbative quantization of cosmological spacetimes in loop quantum cosmology provides insights on the physics of Planck scale and the resolution of big bang singularity. In recent years, rigorous examination of…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Parampreet Singh

All black holes (BHs) in nature are expected to be described by the Kerr vacuum solution of general relativity (GR). However, the Kerr BH interior contains several problematic features such as a Cauchy horizon, a curvature singularity, and…

General Relativity and Quantum Cosmology · Physics 2024-10-23 Prashant Kocherlakota , Ramesh Narayan

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

The occurrence of singularities where spacetime curvature becomes infinite and geodesic evolution breaks down are inevitable events in classical general relativity (GR) unless one chooses an exotic matter violating weak energy condition.…

General Relativity and Quantum Cosmology · Physics 2024-11-05 Bao-Fei Li , Parampreet Singh

A `black hole sector' of non-perturbative canonical quantum gravity is introduced. The quantum black hole degrees of freedom are shown to be described by a Chern-Simons field theory on the horizon. It is shown that the entropy of a large…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. Ashtekar , J. Baez , A. Corichi , K. Krasnov

A class of exact, anisotropic cosmological solutions to the vacuum Brans-Dicke theory of gravity is considered within the context of the pre-big bang scenario. Included in this class are the Bianchi type III, V and VI_h models and the…

General Relativity and Quantum Cosmology · Physics 2016-08-31 D. Clancy , J. E. Lidsey , R. Tavakol

The longstanding issue of general covariance in effective models of quantum gravity is addressed, which arises when canonical quantum gravity leads to a semiclassical model described by an effective Hamiltonian constraint. In the context of…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Cong Zhang , Jerzy Lewandowski , Yongge Ma , Jinsong Yang

We study the effective dynamics of the Schwarzschild black hole interior by introducing entropic deformations derived from generalized superstatistical entropies $S_{+}$ and $S_{-}$. The resulting modified Hamiltonians $\bar{H}_{\pm}$,…

General Relativity and Quantum Cosmology · Physics 2026-04-14 O. Garcia , O. Obregón , J. Ríos Padilla

We construct general anisotropic cosmological scenarios governed by an $f(R)$ gravitational sector. Focusing then on Kantowski-Sachs geometries in the case of $R^n$-gravity, and modelling the matter content as a perfect fluid, we perform a…

General Relativity and Quantum Cosmology · Physics 2011-08-19 Genly Leon , Emmanuel N. Saridakis

It has been proposed that quantum complexity is dual to the volume of the extremal surface, the action of the Wheeler-DeWitt patch, and the spacetime volume of the patch. Recently, a generalized volume-complexity observable was formulated…

High Energy Physics - Theory · Physics 2023-11-27 Xuanhua Wang , Ran Li , Jin Wang