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Related papers: Some generalizations of the Raychaudhuri equation

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General Relativity is considered to be so far the best gravitation theory. However it is quite hard to use in real situations. The root of these difficulties lays in the non-linearity of the theory. Our aim was not to linearize the theory,…

General Physics · Physics 2007-05-23 Gy. Szondy

This paper presents a regularized Newton method (RNM) with generalized regularization terms for unconstrained convex optimization problems. The generalized regularization includes quadratic, cubic, and elastic net regularizations as special…

Optimization and Control · Mathematics 2024-07-11 Yuya Yamakawa , Nobuo Yamashita

We consider a nonlinear partial differential equation for complex-valued functions which is related to the two-dimensional stationary Schrodinger equation and enjoys many properties similar to those of the ordinary differential Riccati…

Analysis of PDEs · Mathematics 2009-11-13 Kira V. Khmelnytskaya , Vladislav V. Kravchenko

Recently, a new strategy to the reconstruction of $f(R)$-gravity models based on the Raychaudhuri equation has been suggested by Choudhury et al. In this paper, utilizing this method, the reconstruction of anisotropic Einstein-Maxwell…

General Relativity and Quantum Cosmology · Physics 2020-06-24 Behzad Tajahmad

A generalized covariant method of analysis applicable to frames for which time is not orthogonal to space, such as spacetime around a star possessing angular momentum or on a rotating disk, is presented. Important aspects of such an…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert D. Klauber

The aim of this article is to promote the use of probabilistic methods in the study of problems in mathematical general relativity. Two new and simple singularity theorems, whose features are different from the classical singularity…

Probability · Mathematics 2011-02-21 Ismael Bailleul

We use the framework used by Bakry and Emery in their work on logarithmic Sobolev inequalities to define a notion of coarse Ricci curvature on smooth metric measure spaces alternative to the notion proposed by Y. Ollivier. This function can…

Differential Geometry · Mathematics 2015-05-18 Antonio Ache , Micah Warren

In 1945 Einstein concluded that [1]: 'The present theory of relativity is based on a division of physical reality into a metric field (gravitation) on the one hand, and into an electromagnetic field and matter on the other hand. In reality…

General Physics · Physics 2016-10-13 Johan Bengtsson

General relativity is extended by promoting the three-dimensional gravitational Chern-Simons term to four dimensions. This entails choosing an embedding coordinate v_\mu -- an external quantity, which we fix to be a non-vanishing constant…

General Relativity and Quantum Cosmology · Physics 2014-11-17 R. Jackiw , S. -Y. Pi

This paper presents a brief but comprehensive introduction to certain mathematical techniques in General Relativity. Familiar mathematical procedures are investigated taking into account the complications of introducing a non trivial…

Mathematical Physics · Physics 2008-11-06 Andrew DeBenedictis

Gravitational waves (GWs) are independent of any particular theory of gravity. The universality of this notion is highlighted by the Raychaudhuri equation (RE), which is independent of any theory of gravity and contains the Ricci tensor…

General Relativity and Quantum Cosmology · Physics 2025-09-29 Sougata Bhunia , Anubhab Dutta , Debashis Gangopadhyay , Goutam Manna

The investigations presented in this study are directed at relativistic modifications of the uncertainty relation derived from the curvature of the background spacetime. These findings generalize previous work which is recovered in the…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Fabian Wagner

Comparing and recognizing metrics can be extraordinarily difficult because of the group of diffeomorphisms. Two metrics, that could even be the same, could look completely different in different coordinates. This is the gauge problem. The…

Differential Geometry · Mathematics 2025-09-22 Tobias Holck Colding , William P. Minicozzi

A generalized divergence theorem is established allowing for domains with inner boundaries. The normal trace of a rough integrand is not a Radon measure; rather, the boundary integral is expressed via a surface functional continuous with…

Analysis of PDEs · Mathematics 2025-10-29 Thomas Ruf

We give necessary and sufficient conditions for the existence of a generalization of R\'enyi divergence, which is defined in terms of a deformed exponential function. If the underlying measure $\mu$ is non-atomic, we found that not all…

Information Theory · Computer Science 2020-08-12 Rui F. Vigelis , Luiza H. F. de Andrade , Charles C. Cavalcante

In this study, the Riccati equation is resolved using the generalized recursive integrating factor method. By applying a non-linear transformation to the dependent variable $y(x)$ of the Riccati equation, a second-order linear differential…

Mathematical Physics · Physics 2025-03-03 Everardo Rivera-Oliva

In this paper the double-sided Talor's approximations are used to obtain generalisations and improvements of some trigonometric inequalities.

Classical Analysis and ODEs · Mathematics 2019-06-12 Branko Malesevic , Tatjana Lutovac , Marija Rasajski , Bojan Banjac

Recent progress concerning regularization of supersymmetric theories is reviewed. Dimensional reduction is reformulated in a mathematically consistent way, and an elegant and general method is presented that allows to study the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dominik Stöckinger

In this paper we generalize the monotonicity formulas of [C] for manifolds with nonnegative Ricci curvature. Monotone quantities play a key role in analysis and geometry; see, e.g., [A], [CM1] and [GL] for applications of monotonicity to…

Differential Geometry · Mathematics 2012-09-24 Tobias Holck Colding , William P. Minicozzi

We investigate the impact of the generalized uncertainty principle proposed by some approaches to quantum gravity such as string theory and doubly special relativity on the cosmology. Using generalized Poisson brackets, we obtain the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Mahdi Rashki , Majid Fathi , Behrang Mostaghel , Sahram Jalalzadeh