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Related papers: On singularity-resolution in mimetic gravity

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In this article, we investigate scalar field cosmology in the coincident $f(Q)$ gravity formalism. We calculate the motion equations of $f(Q)$ gravity under the flat Friedmann-Lema\^{i}tre-Robertson-Walker background in the presence of a…

General Relativity and Quantum Cosmology · Physics 2024-04-12 Sayantan Ghosh , Raja Solanki , P. K. Sahoo

In the context of the late time cosmic acceleration phenomenon, many geometrically modified theories of gravity have been proposed in recent times. In this paper, we have investigated the role of a recently proposed extension of symmetric…

General Relativity and Quantum Cosmology · Physics 2021-08-16 A. S. Agrawal , Laxmipriya Pati , S. K. Tripathy , B. Mishra

In this work, we study the possibility of generalizing solutions of regular black holes with an electric charge, constructed in general relativity, for the $f(G)$ theory, where $G$ is the Gauss-Bonnet invariant. This type of solution arises…

General Relativity and Quantum Cosmology · Physics 2018-08-20 Marcos V. de S. Silva , Manuel E. Rodrigues

We study the bounce cosmology to construct a singularity-free $f(\mathcal{R})$ model using the reconstruction technique. The formulation of the $f(\mathcal{R})$ model is based on the Raychaudhari equation, a key element employed in…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo , Kazuharu Bamba

We consider the quantization of the complete extension of the Schwarzschild space-time using spherically symmetric loop quantum gravity. We find an exact solution corresponding to the semi-classical theory. The singularity is eliminated but…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Rodolfo Gambini , Jorge Pullin

We review and extend some recent results concerning the analysis of spacetime singularities in four-dimensional higher spin gravity, summarizing how the coupling of the gravitational field to massless higher spins may provide resolution…

High Energy Physics - Theory · Physics 2022-05-03 Carlo Iazeolla , Per Sundell

It is not easy to treat the spacetime with horizon(s) in the standard mimetic gravity. The solution to this problem has been presented in Phys.~Lett.~B 830 (2022), 137140, where it was suggested to modify the Lagrange multiplier constraint.…

General Relativity and Quantum Cosmology · Physics 2024-09-24 Shin'ichi Nojiri , Sergei D. Odintsov

We study the "improved dynamics" for the treatment of spherically symmetric space-times in loop quantum gravity introduced by Chiou {\em et al.} in analogy with the one that has been constructed by Ashtekar, Pawlowski and Singh for the…

General Relativity and Quantum Cosmology · Physics 2020-10-28 R. Gambini , J. Olmedo , J. Pullin

The future finite-time singularities emerging in alternative gravity dark energy models are classified and studied in Jordan and Einstein frames. It is shown that such singularity may occur even in flat spacetime for the specific choice of…

High Energy Physics - Theory · Physics 2009-06-30 S. Capozziello , M. De Laurentis , S. Nojiri , S. D. Odintsov

We seek to obtain a new class of exact solutions of regular black holes in $f(T)$ Gravity with non-linear electrodynamics material content, with spherical symmetry in $4D$. The equations of motion provide the regaining of various solutions…

General Relativity and Quantum Cosmology · Physics 2015-11-02 Ednaldo L. B. Junior , Manuel E. Rodrigues , Mahouton J. S. Houndjo

We present a covariant model of a spherically symmetric black hole with corrections motivated by loop quantum gravity. The effective modifications, parametrized by a positive constant $\lambda$, are implemented through a canonical…

General Relativity and Quantum Cosmology · Physics 2022-10-07 Asier Alonso-Bardaji , David Brizuela , Raül Vera

We consider nonlocal modification of the Einstein theory of gravity in framework of the pseudo-Riemannian geometry. The nonlocal term has the form $\mathcal{H}(R) \mathcal{F}(\Box)\mathcal {G}(R)$, where $\mathcal{H}$ and $\mathcal{G}$ are…

High Energy Physics - Theory · Physics 2015-08-25 Ivan Dimitrijevic , Branko Dragovich , Jelena Grujic , Zoran Rakic

Large-distance modification of gravity may be the mechanism for solving the cosmological constant problem. A simple model of the large-distance modification -- four-dimensional (4D) gravity with the hard mass term-- is problematic from the…

High Energy Physics - Theory · Physics 2009-11-10 G. Gabadadze , M. Shifman

We investigate bouncing scenario in the modified $f(T)$ gravity, $T$ being the torsion scalar. Attention is attached to the reconstruction of $f(T)$ able to describe type IV singular bouncing evolution, where we adopt as assumption that the…

General Relativity and Quantum Cosmology · Physics 2019-09-25 P. H. Logbo , M. J. S. Houndjo

Recent results show that important singularities in General Relativity can be naturally described in terms of finite and invariant canonical geometric objects. Consequently, one can write field equations which are equivalent to Einstein's…

General Relativity and Quantum Cosmology · Physics 2014-03-06 Ovidiu Cristinel Stoica

We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density contribution from the fermions. Our theory is…

General Relativity and Quantum Cosmology · Physics 2014-12-10 Stephon Alexander , Cosimo Bambi , Antonino Marciano , Leonardo Modesto

We discuss the cosmology of recently proposed Horava-Lifshitz f(R) gravity. In particular, we derive the modified Hubble equation that reduces to the standard HL gravity case in appropriate limit. We show how the bounce solutions in this…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-13 Sayan K. Chakrabarti , Koushik Dutta , Anjan A. Sen

In this paper we investigate how to realize various quite well known cosmological bouncing models in the context of the recently developed unimodular $F(R)$ gravity. Particularly, we shall study the matter bounce scenario, the singular…

General Relativity and Quantum Cosmology · Physics 2016-05-04 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

This work tests the no-hair conjecture in $f(R)$ gravity models. No-hair conjecture asserts that all black holes in General Relativity coupled to any matter must be Kerr-Newman type. However, the conjecture fails in some cases with…

General Relativity and Quantum Cosmology · Physics 2024-05-21 Alan Sunny , Semin Xavier , S. Shankaranarayanan

We study gravity coupled to a cosmological constant and a scale but not conformally invariant sector. In Minkowski vacuum, scale invariance is spontaneously broken. We consider small fluctuations around the Minkowski vacuum. At the…

High Energy Physics - Theory · Physics 2016-06-22 Stefan Forste , Paul Manz
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