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By using point-coupling versions of finite range nuclear relativistic mean field models containing cubic and quartic self interactions in the scalar field $\sigma$, a nonrelativistic limit is achieved. This approach allows an analytical…

Nuclear Theory · Physics 2014-09-18 B. M. Santos , M. Dutra , O. Lourenço , A. Delfino

In this work, one examines how the presence of a non-minimal coupling between the spacetime curvature and matter affects the evolution of cosmological perturbations around a homogeneous and isotropic Universe and hence the formation of…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Orfeu Bertolami , Pedro Frazão , Jorge Páramos

We prove the generalized second law (GSL) for higher curvature gravity theories when the matter sector is non-minimally coupled. The validity of our proof is in the regime of linearized fluctuations about equilibrium black holes, which is…

General Relativity and Quantum Cosmology · Physics 2024-07-09 Prateksh Dhivakar , Krishna Jalan

We review recent progress in 2D gravity coupled to $d<1$ conformal matter, based on a representation of discrete gravity in terms of random matrices. We discuss the saddle point approximation for these models, including a class of related…

High Energy Physics - Theory · Physics 2010-11-01 P. Di Francesco , P. Ginsparg , J. Zinn-Justin

Using minimalist assumptions we develop a natural functional decomposition for the spacetime metric, and explicit tractable formulae for the surface gravities, in arbitrary stationary circular (PT symmetric) axisymmetric spacetimes. We…

General Relativity and Quantum Cosmology · Physics 2023-05-30 Joshua Baines , Matt Visser

In this paper we develop methods to extend the minimal hypersurface approach to positive scalar curvature problems to all dimensions. This includes a proof of the positive mass theorem in all dimensions without a spin assumption. It also…

Differential Geometry · Mathematics 2017-04-20 Richard Schoen , Shing-Tung Yau

A central aspect of the cosmological constant problem is to understand why vacuum energy does not gravitate. In order to account for this observation, while allowing for nontrivial dynamics of the quantum vacuum, we motivate a novel…

General Relativity and Quantum Cosmology · Physics 2020-02-05 Stephon Alexander , Raúl Carballo-Rubio

We study the evolution of cosmological perturbations around a homogeneous and isotropic background in the framework of the non-minimal torsion-matter coupling extension of $f(T)$ gravity. We are concerned with the effects of the non-minimal…

General Relativity and Quantum Cosmology · Physics 2018-10-09 Manuel Gonzalez-Espinoza , Giovanni Otalora , Joel Saavedra , Nelson Videla

GR can be interpreted as a theory of evolving 3-geometries. A recent such formulation, the 3-space approach of Barbour, Foster and \'{O} Murchadha, also permits the construction of a limited number of other theories of evolving…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Edward Anderson

We generalize tensor-scalar theories of gravitation by the introduction of an abnormally weighting type of energy. This theory of tensor-scalar anomalous gravity is based on a relaxation of the weak equivalence principle that is now…

Astrophysics · Physics 2009-01-14 J. -M. Alimi , A. Füzfa

I argue that the (extended) Standard Model (SM) of particle physics and the renormalizable Feynman-Weinberg theory of quantum gravity comprise a theory of everything. I show that imposing the appropriate cosmological boundary conditions…

High Energy Physics - Theory · Physics 2008-11-26 Frank J. Tipler

General Relativity assumes that spacetime is fully described by the metric alone. An alternative is the so called Palatini formalism where the metric and the connections are taken as independent quantities. The metric-affine theory of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thomas P. Sotiriou , Stefano Liberati

Over the last two years, the canonical approach to quantum gravity based on connections and triads has been put on a firm mathematical footing through the development and application of a new functional calculus on the space of gauge…

High Energy Physics - Theory · Physics 2015-06-26 Abhay Ashtekar

The rigidity of the positive mass theorem states that the only complete asymptotically flat manifold of nonnegative scalar curvature and zero mass is Euclidean space. We prove a corresponding stability theorem for spaces that can be…

Differential Geometry · Mathematics 2015-06-19 Lan-Hsuan Huang , Dan A. Lee

We study the self-compactification of extra dimensions via higher curvature gravity, f(R), where f(R) is the generic function of the Ricci scalar R. First, we reduce pure f(R) theory to a scalar-tensor theory by a conformal transformation.…

High Energy Physics - Theory · Physics 2011-02-16 Beyhan Pulice , Sukru Hanif Tanyildizi

Is the universe finite or infinite, and what shape does it have? These fundamental questions, of which relatively little is known, are typically studied within the context of the standard model of cosmology where the universe is assumed to…

General Relativity and Quantum Cosmology · Physics 2022-06-02 Gregory J. Galloway , Marcus A. Khuri , Eric Woolgar

A complete canonical formulation of general covariance makes it possible to construct new modified theories of gravity that are not of higher-curvature form, as shown here in a spherically symmetric setting. The usual uniqueness theorems…

General Relativity and Quantum Cosmology · Physics 2024-04-10 Martin Bojowald , Erick I. Duque

We consider a recently proposed class of extended teleparallel theories of gravity, which entail a scalar field which is non-minimally coupled to the torsion of a flat, metric-compatible connection. This class of scalar-torsion theories of…

General Relativity and Quantum Cosmology · Physics 2020-01-24 Elena D. Emtsova , Manuel Hohmann

Inserting a varying Lambda in Einstein's field equations can be made consistent with the Bianchi identities by allowing for torsion, without the need to add scalar field degrees of freedom. In the minimal such theory, Lambda is totally free…

General Relativity and Quantum Cosmology · Physics 2019-10-07 Stephon Alexander , Marina Cortês , Andrew R. Liddle , João Magueijo , Robert Sims , Lee Smolin

In this paper, a new generalised gravity-matter coupled theory of gravity is presented. This theory is constructed by assuming an action with an arbitrary function $f(T,B,L_m)$ which depends on the scalar torsion $T$, the boundary term…

General Relativity and Quantum Cosmology · Physics 2018-04-24 Sebastian Bahamonde