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Related papers: String-inspired Teleparallel Cosmology

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We investigate the cosmological perturbations around FLRW solutions to non- linear massive gravity with a new effective coupling to matter proposed recently. Unlike the case with minimal matter coupling, all five degrees of freedom in the…

High Energy Physics - Theory · Physics 2015-06-23 A. Emir Gümrükçüoğlu , Lavinia Heisenberg , Shinji Mukohyama

This is a short review on strings in curved spacetimes. We start by recalling the classical and quantum string behaviour in singular plane waves backgrounds. We then report on the string behaviour in cosmological spacetimes (FRW, de Sitter,…

High Energy Physics - Theory · Physics 2007-05-23 H. J. de Vega

We discuss linear perturbations of the most general class of teleparallel spacetimes with cosmological symmetry, and perform a decomposition of these perturbations into irreducible components. We then study their behavior under gauge…

General Relativity and Quantum Cosmology · Physics 2021-01-12 Manuel Hohmann

Teleparallel gravity has significantly increased in popularity in recent decades, bringing attention to Einstein's other theory of gravity. In this Review, we relate this form of geometry to the broader metric-affine approach to forming…

We consider $f(R,T)$ modified theories of gravity in the context of string theory inspired dilaton gravity. We deal with a specific model that under certain conditions describes the late time Universe in accord with observational data in…

High Energy Physics - Theory · Physics 2024-03-11 F. A. Brito , C. H. A. B. Borges , J. A. V. Campos , F. G. Costa

As a classical approach, the dynamics of the Universe, influenced by its dark components, are unveiled through prior modifications of Einstein's equations. Cosmography, on the other hand, is a highly efficient tool for reconstructing any…

General Relativity and Quantum Cosmology · Physics 2024-07-19 Sai Swagat Mishra , N. S. Kavya , P. K. Sahoo , V. Venkatesha

The study of cosmological perturbation theory in $f(T)$ gravity is a topic of great interest in teleparallel gravity since this is one of the simplest generalizations of the theory that modifies the teleparallel equivalent of general…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Sebastian Bahamonde , Konstantinos F. Dialektopoulos , Manuel Hohmann , Jackson Levi Said , Christian Pfeifer , Emmanuel N. Saridakis

The aim of these lectures is to give an introduction to several topics which lie at the intersection of string theory, gravity theory and gravity phenomenology. One successively reviews: (i) the "membrane" approach to the dissipative…

High Energy Physics - Theory · Physics 2008-02-29 Thibault Damour , Marc Lilley

In this paper we consider an inflating universe with long straight cosmic string along z-axis. We show that the effect of cosmic string can be taken as a perturbation on the background of FRW metric. Then by doing cosmological perturbations…

General Relativity and Quantum Cosmology · Physics 2024-05-07 S. Azar Ag Galeh , A. M. Abbassi , M. H. Abbassi

We consider Kasner-type static, cylindrically symmetric interior string solutions in the $f\left(R,L_m\right)$ theory of modified gravity. The physical properties of the string are described by an anisotropic energy-momentum tensor…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Tiberiu Harko , Matthew J. Lake

A synthetic report of the advances in the study of classical and quantum string dynamics in curved backgrounds is provided, namely: the new feature of multistring solutions; the effect of a cosmological constant and of spacial curvature on…

High Energy Physics - Theory · Physics 2011-07-19 Norma G. Sanchez

We study the implications of a scalar-tensorial gravity for the metric of an isolated self-gravitating superconducting cosmic string. These modifications are induced by an arbitrary coupling of a massless scalar field to the usual tensorial…

General Relativity and Quantum Cosmology · Physics 2016-11-03 C. N. Ferreira , M. E. X. Guimaraes , J. A. Helayel-Neto

The actions of the ``$R=T$'' and string-inspired theories of gravity in (1+1) dimensions are generalized into one single action which is characterized by two functions. We discuss differing interpretations of the matter stress-energy…

General Relativity and Quantum Cosmology · Physics 2010-04-06 J. S. F. Chan , R. B. Mann

String theory provides the only consistent framework so far that unifies all interactions including gravity. We discuss gravity and cosmology in string theory. Conventional notions from general relativity like geometry, topology etc. are…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Elias Kiritsis , Costas Kounnas

We study linear cosmological perturbations in the most general teleparallel gravity setting, where gravity is mediated by the torsion and nonmetricity of a flat connection alongside the metric. For a general linear perturbation of this…

General Relativity and Quantum Cosmology · Physics 2023-12-22 Lavinia Heisenberg , Manuel Hohmann

Inspired by String T-duality and taking into account the zero-point length correction, $l_0$, to the gravitational potential, we construct modified Friedmann equations by applying the first law of thermodynamics on the apparent horizon of…

General Relativity and Quantum Cosmology · Physics 2024-12-17 Giuseppe Gaetano Luciano , Ahmad Sheykhi

The Gauss-Bonnet invariant connects foundational aspects of geometry with physical phenomena in a variety of ways. Teleparallel gravity offers a novel direction in which to use the Gauss-Bonnet invariant to go beyond standard cosmology. In…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Shivam Kumar Mishra , Jackson Levi Said , B. Mishra

Teleparallel gravity offers a new avenue in which to construct gravitational models beyond general relativity. While teleparallel gravity can be framed in a way to be dynamically equivalent to general relativity, its modifications are…

General Relativity and Quantum Cosmology · Physics 2021-01-28 Sebastian Bahamonde , Viktor Gakis , Stella Kiorpelidi , Tomi Koivisto , Jackson Levi Said , Emmanuel N. Saridakis

We provide a rigorous proof for the existence of homogeneous, isotropic and globally singularity-free cosmological solutions in Einstein-dilaton-Gauss-Bonnet (EdGB) gravity with exponential coupling. While numerical studies suggested such…

Analysis of PDEs · Mathematics 2025-12-02 Chihang He , Chao Liu

The properties of a string-inspired two-dimensional theory of gravity are studied. The post-Newtonian and weak-field approximations, `stellar' structure and cosmological solutions of this theory are developed. Some qualitative similarities…

High Energy Physics - Theory · Physics 2009-10-22 R. B. Mann , S. F. Ross
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