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Related papers: Anisotropy Strikes Back: Modified Gravity and Dark…

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We propose a method to study and constrain modified gravity theories for dark matter using CMB temperature anisotropies and polarization. We assume that the theories considered here have already passed the matter power-spectrum test of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Baojiu Li , John D. Barrow , David F. Mota , HongSheng Zhao

Decaying dark matter particles could be indirectly detected as an excess over a simple power law in the energy spectrum of the diffuse extragalactic gamma-ray background. Furthermore, since the Earth is not located at the center of the…

High Energy Physics - Phenomenology · Physics 2014-11-20 Alejandro Ibarra , David Tran , Christoph Weniger

We consider the Hamiltonian formulation of Horava gravity in arbitrary dimensions, which has been proposed as a renormalizable gravity model for quantum gravity without the ghost problem. We study the "full" constraint analysis of the…

High Energy Physics - Theory · Physics 2020-08-26 Deniz O. Devecioglu , Mu-In Park

The Hamiltonian of classical anti-de Sitter gravity is a pure boundary term on-shell. If this remains true in non-perturbative quantum gravity then i) boundary observables will evolve unitarily in time and ii) the algebra of boundary…

General Relativity and Quantum Cosmology · Physics 2009-02-18 Donald Marolf

In this work, we have considered dilaton dark energy model in Weyl-scaled induced gravitational theory in presence of barotropic fluid. It is to be noted that the dilaton field behaves as a quintessence. Here we have discussed the role of…

General Physics · Physics 2015-05-28 Piyali Bagchi Khatua , Shuvendu Chakraborty , Ujjal Debnath

To solve the hierarchy problem, the relaxion must remain trapped in the correct minimum, even if the electroweak symmetry is restored after reheating. In this scenario, the relaxion starts rolling again until the backreaction potential,…

High Energy Physics - Phenomenology · Physics 2021-09-29 Abhishek Banerjee , Eric Madge , Gilad Perez , Wolfram Ratzinger , Pedro Schwaller

In this work, we investigate non-interacting holographic dark energy (HDE) with the Hubble radius as the infrared cutoff in Einstein-Cartan gravity. We derive the Einstein-Cartan equations from the action principle and obtain Friedmann-like…

General Relativity and Quantum Cosmology · Physics 2026-05-22 Yongjun Yun , Jungjai Lee

We carry out fully 3-dimensional simulations of evolution from self-similar, spherically symmetric linear perturbations of a Cold Dark Matter dominated Einstein-de Sitter universe. As a result of the radial orbit instability, the haloes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Mark Vogelsberger , Roya Mohayaee , Simon D. M. White

Because the gravitational Hamiltonian is a pure boundary term on-shell, asymptotic gravitational fields store information in a manner not possible in local field theories. This fact has consequences for both perturbative and…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Donald Marolf

This paper is a study of the water wave problem in a two-dimensional domain of infinite depth in the presence of nonzero constant vorticity. A goal is to describe the effects of uniform shear flow on the modulation of weakly nonlinear…

Analysis of PDEs · Mathematics 2022-10-19 Philippe Guyenne , Adilbek Kairzhan , Catherine Sulem

Motivated by anomalies in cosmic microwave background observations, we investigate the implications of $f(Q, T)$ gravity in Bianchi type-I spacetime, aiming to characterize the universe's spatially homogeneous and anisotropic properties. By…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-30 A. Zhadyranova , M. Koussour , V. Zhumabekova , O. Donmez , S. Muminov , J. Rayimbaev

A starting point for the present work was the statement recently discussed in the literature that two Hamiltonian formulations for the theory of gravity, the one proposed by Dirac and the other by Arnowitt - Deser - Misner, may not be…

General Relativity and Quantum Cosmology · Physics 2011-03-07 T. P. Shestakova

We propose a theoretically consistent modification of gravity in the infrared, which is compatible with all current experimental observations. This is an analog of Higgs mechanism in general relativity, and can be thought of as arising from…

High Energy Physics - Theory · Physics 2009-11-10 Nima Arkani-Hamed , Hsin-Chia Cheng , Markus A. Luty , Shinji Mukohyama

The pure Brans-Dicke (BD) gravity with or without the cosmological constant $\Lambda $ has been taken as a model theory for the dark matter. Indeed, there has been a consensus that unless one modifies either the standard theory of gravity,…

Astrophysics · Physics 2007-08-21 Hongsu Kim

We show that the formation/evaporation of Black Holes (BH) unitarizes quantum gravity at all the orders of the perturbation theory. Non-perturbative quantum effects save the scattering amplitudes from any polynomial divergences. Such a…

High Energy Physics - Theory · Physics 2020-12-02 Andrea Addazi

First, we describe the construction of a new type of gravity-matter models based on the formalism of non-Riemannian space-time volume forms - alternative generally covariant integration measure densities (volume elements) defined in terms…

General Relativity and Quantum Cosmology · Physics 2017-12-29 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

We use the Wetterich equation for foliated spacetimes to study the RG flow of projectable Horava-Lifshitz gravity coupled to n Lifshitz scalars. Using novel results for anisotropic heat kernels, the matter-induced beta functions for the…

General Relativity and Quantum Cosmology · Physics 2014-10-29 Giulio D'Odorico , Frank Saueressig , Marrit Schutten

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

The evolution of density perturbations is analysed in a modified theory of gravity with a nonminimal coupling between curvature and matter. We consider the broken degeneracy between the choices of matter Lagrangian for a perfect fluid,…

General Relativity and Quantum Cosmology · Physics 2026-01-26 Miguel Barroso Varela , Orfeu Bertolami

We consider a generalization of the Lemaitre-Tolman-Bondi (LTB) solutions by keeping the LTB metric but replacing its dust matter source by an imperfect fluid with anisotropic pressure $\Pi_{ab} $. Assuming that total matter-energy density…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Roberto A. Sussman , Mustapha Ishak