English
Related papers

Related papers: Avoidance of Singularity and Global Non-Conservati…

200 papers

We perform a phase space analysis of a generalized modified gravity theory with nonminimally coupling between geometry and matter. We apply the dynamical system approach to this generalized model and find that in the cosmological context,…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Rui An , Xiaodong Xu , Bin Wang , Yungui Gong

Although the Universe is far from understood, we are fairly confident about some key features: Special Relativity (SR) describes the kinematics of inertial frames; General Relativity (GR) explains gravitation; the Universe had a beginning…

General Physics · Physics 2007-05-23 Alasdair Macleod

Using the fluid representation, we formulate the conditions for the appearance of all four types finite-time future singularity in modified gravity in accelerating FRW universe. It stressed that number of standard quintessence/phantom DE…

High Energy Physics - Theory · Physics 2014-11-20 Shin'ichi Nojiri , Sergei D. Odintsov

Introduced herein are the foundations of Global Time Theory (GTT) that further develop the General Relativity (GR). GTT is significantly different from GR in the general physical concepts, but retains 90% of the mathematical structure and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. E. Burlankov

Mach's principle is surely one of those tantalizingly beautiful concepts in physics which remain elusive. Though General Relativity (GR) was conceived in the spirit of realizing it, the theory failed to fulfill this expectation. Here a…

General Relativity and Quantum Cosmology · Physics 2015-08-19 Ram Gopal Vishwakarma

We present a concise description of the basic features of gravity-matter models based on the formalism of non-canonical spacetime volume-forms in its two versions: the method of non-Riemannian volume-forms (metric-independent covariant…

General Relativity and Quantum Cosmology · Physics 2019-10-15 David Benisty , Eduardo Guendelman , Alexander Kaganovich , Emil Nissimov , Svetlana Pacheva

The Rastall's theory is a modification of the General Relativity theory leading to a different expression for the conservation law in the matter sector compared with the usual one. It has been argued recently that such a theory may have…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-29 C. E. M. Batista , J. C. Fabris , M. Hamani Daouda

According to conventional modelling by general relativity the collapse of radially symmetric gravitating objects may end in a singular state. But by inclusion of potential energy into the energy tensor, which is required to guarantee global…

General Physics · Physics 2013-03-27 Ernst Fischer

Energy conservation has the status of a fundamental physical principle. However, measurements in quantum mechanics do not comply with energy conservation. Therefore, it is expected that a more fundamental theory of gravity -- one that is…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Y. Bonder , J. E. Herrera , A. M. Rubiol

Singularities in Newton's gravitation, in general relativity (GR), in Coulomb's law, and elsewhere in classical physics, stem from two ill conceived assumptions: a) there are point-like entities with finite masses, charges, etc., packed in…

General Physics · Physics 2025-03-26 Yousef Sobouti , Haidar Sheikhahmadi

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger , Phillip Zukin

Relying on a fundamental empirical identity of heavy and inertial mass it is proposed to bring a status of general theory of relativity (GTR) of Einstein up to a level of Unified Field Theory. To do this, a thoroughgoing revision of…

General Physics · Physics 2016-09-08 Boris Mordvinov

We present a general form for the solution of an expanding general-relativistic Friedmann universe that encounters a singularity at finite future time. The singularity occurs in the material pressure and acceleration whilst the scale…

General Relativity and Quantum Cosmology · Physics 2009-11-10 John D. Barrow

We provide a new extension of general relativity (GR) which has the remarkable property of being more constrained than GR plus a cosmological constant, having one less free parameter. This is implemented by allowing the cosmological…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Stephon Alexander , Marina Cortês , Andrew R. Liddle , João Magueijo , Robert Sims , Lee Smolin

Theory of general relativity (GR) has been scrutinized by experts for almost a century and describes accurately all gravitational phenomena ranging from the solar system to the universe. However, this success is achieved provided one admits…

General Physics · Physics 2013-07-02 Ram Gopal Vishwakarma

We invoke the global properties of the actual GTR field equations for spherical collapse to directly show that the condition for formation of trapped surfaces, 2GM/R >1 is not allowed by GTR. And therefore all singularity theorems based on…

Astrophysics · Physics 2007-05-23 Abhas Mitra

The general theory of relativity (GR) was proposed with an aim of incorporating Mach's principle mathematically. Despite early hopes, it became evident that GR did not follow Mach's principle. Over time, multiple researchers attempted to…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Santanu Das

In this work, we study the possibility of finite-time future cosmological singularities appearing in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. We present the theory in both the…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

I briefly discuss some attempts to construct a consistent modification to General Relativity (GR) that might explain the observed late-time acceleration of the universe and provide an alternative to dark energy. I mention the issues facing…

Astrophysics · Physics 2008-11-26 Mark Trodden

In this work, we discuss the conditions that allow the establishment of an equivalence between $f(R,T)=R+\lambda h(T)$ gravity models and General Relativity (GR) coupled to a modified matter sector. We do so by considering a $D$-dimensional…

General Relativity and Quantum Cosmology · Physics 2025-12-12 Gonzalo J. Olmo , Miguel A. S. Pinto