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Related papers: Modified gravity inside astrophysical bodies

200 papers

Gravitational waves (GW) are generally affected by modification of a gravity theory during propagation in cosmological distance. We numerically perform a quantitative analysis on Horndeski theory at cosmological scale to constrain the…

General Relativity and Quantum Cosmology · Physics 2018-05-28 Shun Arai , Atsushi Nishizawa

Linear cosmological perturbations of a large class of modified gravity and dark energy models can be unified in the effective field theory of cosmic acceleration, encompassing Horndeski scalar-tensor theories and beyond. The fully available…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-25 Lucas Lombriser , Andy Taylor

We bring together two popular formalisms which generically parameterise deviations from General Relativity on astrophysical and cosmological scales, namely the parameterised post-Newtonian (PPN) formalism and the effective field theory…

General Relativity and Quantum Cosmology · Physics 2021-01-29 Cyril Renevey , Joe Kennedy , Lucas Lombriser

In a mean-field approximation within Kinetic Field Theory, it is possible to derive an accurate analytic expression for the power spectrum of present-day non-linear cosmic density fluctuations. It depends on the theory of gravity and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-13 Alexander Oestreicher , Harshda Saxena , Niklas Reinhardt , Elena Kozlikin , Johannes Dombrowski , Matthias Bartelmann

A new conception is proposed in Ref.\cite{Verlinde:2010hp,Padmanabhan:2009kr} that gravity is one kind of entropic force. In this letter, we try to discuss its applications to the modified gravities by using three different corrections to…

High Energy Physics - Theory · Physics 2011-08-05 Yi Zhang , Yun-gui Gong , Zong-Hong Zhu

A subclass of the Horndeski modified gravity theory we call No Slip Gravity has particularly interesting properties: 1) a speed of gravitational wave propagation equal to the speed of light, 2) equality between the effective gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-01 Eric V. Linder

We study how the Vainshtein mechanism operates in the most general scalar-tensor theories with second-order equations of motion. The field equations of motion, which can be also applicable to most of other screening scenarios proposed in…

General Relativity and Quantum Cosmology · Physics 2013-09-02 Ryotaro Kase , Shinji Tsujikawa

In general, modified gravity theories are modifications or extensions of Einstein's general relativity. Some of them give rise to additional scalar degrees of freedom in Nature. If these scalar fields exist and are light enough, they should…

General Relativity and Quantum Cosmology · Physics 2019-12-12 Christian Käding

We study the imprints that theories of gravity beyond GR can leave on the lensing signal around line of sight directions that are predominantly halo-underdense (called troughs) and halo-overdense. To carry out our investigations, we…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-27 Alexandre Barreira , Sownak Bose , Baojiu Li , Claudio Llinares

Cosmic acceleration may be due to modifications of cosmic gravity and to test this we need robust connections between theory and observations. However, in a model independent approach like effective field theory or a broad class like…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-31 Eric V. Linder

We investigate the efficiency of screening mechanisms in the hybrid metric-Palatini gravity. The value of the field is computed around spherical bodies embedded in a background of constant density. We find a thin shell condition for the…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Marcelo Vargas dos Santos , Jailson S. Alcaniz , David F. Mota , Salvatore Capozziello

In many generalized models of gravity, perfect fluids in cosmology give rise to gravitational slip. Simultaneously, in very broad classes of such models, the propagation of gravitational waves is altered. We investigate the extent to which…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-03 Ignacy Sawicki , Ippocratis D. Saltas , Mariele Motta , Luca Amendola , Martin Kunz

This thesis investigates compact astrophysical objects within modified theories of gravity, focusing on neutron stars and strange stars. The work studies their internal structure, equilibrium, and stability in gravitational frameworks based…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Sneha Pradhan

Emergent modified gravity presents a new class of gravitational theories in which the structure of space-time with Riemannian geometry of a certain signature is not presupposed. Relying on crucial features of a canonical formulation, the…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Martin Bojowald , Erick I. Duque , Dennis Hartmann

Alternative theories of gravity typically invoke an environment-dependent screening mechanism to allow phenomenologically interesting deviations from general relativity (GR) to manifest on larger scales, while reducing to GR on small…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-28 Magnus Fagernes Ivarsen , Philip Bull , Claudio Llinares , David F. Mota

We consider metric-affine scenarios where a modified gravitational action is sourced by electrovacuum fields in a three dimensional space-time. Such scenarios are supported by the physics of crystalline structures with microscopic defects…

General Relativity and Quantum Cosmology · Physics 2015-08-13 Cosimo Bambi , M. Ghasemi-Nodehi , D. Rubiera-Garcia

Modified gravity theories have richer observational consequences for large-scale structure than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine…

Astrophysics · Physics 2009-02-20 Bhuvnesh Jain , Pengjie Zhang

There has been a lot of research interest in modified gravity theories which utilise the Vainshtein mechanism to recover standard general relativity in regions with high matter density, such as the Dvali-Gabadadze-Porrati and Galileon…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

The review is devoted to consideration of possible observational consequences of modified gravity theories, suggested for explanation of the contemporary accelerated expansion of the universe. The major attention is paid to F(R)-models. It…

General Relativity and Quantum Cosmology · Physics 2019-11-11 Elena Arbuzova

We consider the Newtonian limit of modified theories of gravity that include inverse powers of the curvature in the action in order to explain the cosmic acceleration. It has been shown that the simplest models of this kind are in conflict…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Ignacio Navarro , Karel Van Acoleyen