English
Related papers

Related papers: Hyperbolicity and Constrained Evolution in Lineari…

200 papers

Einstein's equations for a 4+n-dimensional inhomogeneous space-time are presented, and a special family of solutions is exhibited for an arbitrary n. The solutions depend on two arbitrary functions of time. The time development of a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Santiago E. Perez Bergliaffa

The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We…

General Relativity and Quantum Cosmology · Physics 2015-11-11 Vitor Cardoso , Leonardo Gualtieri , Carlos Herdeiro , Ulrich Sperhake

Evolutionary algorithms have been frequently applied to constrained continuous optimisation problems. We carry out feature based comparisons of different types of evolutionary algorithms such as evolution strategies, differential evolution…

Artificial Intelligence · Computer Science 2015-09-24 Shayan Poursoltan , Frank Neumann

Theoretical analyses of evolution strategies are indispensable for gaining a deep understanding of their inner workings. For constrained problems, rather simple problems are of interest in the current research. This work presents a…

Neural and Evolutionary Computing · Computer Science 2019-08-12 Patrick Spettel , Hans-Georg Beyer

Gravitational waves allow us to test general relativity in the highly dynamical regime. While current observations have been consistent with waves emitted by quasi-circular binaries, eccentric binaries may also produce detectable signals in…

General Relativity and Quantum Cosmology · Physics 2020-08-26 Blake Moore , Nicolás Yunes

We analyze the equations of relativistic magnetized plasma dynamics in the limiting case that electromagnetic stress-energy is dominant over pressure and rest mass energy density. The naive formulation of these equations is shown to be not…

General Relativity and Quantum Cosmology · Physics 2013-07-31 Harald P. Pfeiffer , Andrew I. MacFadyen

The complete theory of cosmological evolution's macroscopic description is constructed with a help of self-consistent field. The theory includes a subsystem of linear equations of perturbations' evolution and nonlinear macroscopic Einstein…

General Relativity and Quantum Cosmology · Physics 2020-07-09 Yu. G. Ignat'ev

We show that well-posed, conformally-decomposed formulations of the 3+1 Einstein equations can be obtained by densitizing the lapse and by combining the constraints with the evolution equations. We compute the characteristics structure and…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Simonetta Frittelli , Oscar A. Reula

In the 3+1 framework of the Einstein equations for the case of vanishing shift vector and arbitrary lapse, we calculate explicitly the four boundary equations arising from the vanishing of the projection of the Einstein tensor along the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Simonetta Frittelli , Roberto Gomez

We consider a new variant of cosmological perturbation theory that has been designed specifically to include non-linear density contrasts on scales 100 Mpc, while still allowing for linear fluctuations on larger scales. This theory is used…

General Relativity and Quantum Cosmology · Physics 2019-04-08 Christopher S. Gallagher , Timothy Clifton

We study step-wise time approximations of non-linear hyperbolic initial value problems. The technique used here is a generalization of the minimizing movements method, using two time-scales: one for velocity, the other (potentially much…

Numerical Analysis · Mathematics 2024-04-05 Antonín Češík , Sebastian Schwarzacher

Towards the investigation of the full dynamics in higher-dimensional and/or stringy gravitational model, we present the basic equations of the Einstein-Gauss-Bonnet gravity theory. We show $(N+1)$-dimensional version of the ADM…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Takashi Torii , Hisa-aki Shinkai

Here we prove the linear stability of a family of `$n+1$'-dimensional Friedmann Lema\^{i}tre Robertson Walker (FLRW) cosmological models of general relativity. We show that the solutions to the linearized Einstein-Euler field equations…

General Relativity and Quantum Cosmology · Physics 2021-10-01 Puskar Mondal

The linear Einstein-Boltzmann equations describe the evolution of perturbations in the universe and its numerical solutions play a central role in cosmology. We revisit this system of differential equations and present a detailed…

General Relativity and Quantum Cosmology · Physics 2017-10-04 Sharvari Nadkarni-Ghosh , Alexandre Refregier

We study the evolution of a self-gravitating compressible fluid in spherical symmetry and we prove the existence of weak solutions with bounded variation for the Einstein-Euler equations of general relativity. We formulate the initial value…

General Relativity and Quantum Cosmology · Physics 2021-06-17 Annegret Y. Burtscher , Philippe G. LeFloch

We show that generalizations of classical and quantum dynamics with two times lead to fundamentally constrained evolution. At the level of classical physics, Newton's second law is extended and exactly integrated in $1+2$ dimensional space,…

Quantum Physics · Physics 2016-10-05 E. Piceno , A. Rosado , E. Sadurní

We survey some results on scalar curvature and properties of solutions to the Einstein constraint equations. Topics include an extended discussion of asymptotically flat solutions to the constraint equations, including recent results on the…

Differential Geometry · Mathematics 2011-02-25 Justin Corvino , Daniel Pollack

A new numerical scheme to solve the Einstein field equations based upon the generalized harmonic decomposition of the Ricci tensor is introduced. The source functions driving the wave equations that define generalized harmonic coordinates…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Frans Pretorius

In this paper we consider singular timelike spherical hypersurfaces embedded in a $D$-dimensional spherically symmetric bulk spacetime which is an electrovacuum solution of Einstein equations with cosmological constant. We analyse the…

General Relativity and Quantum Cosmology · Physics 2019-03-19 Marcos A. Ramirez , Daniel Aparicio

In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for…

Computational Physics · Physics 2016-02-17 E. Ilseven , M. Mendoza
‹ Prev 1 8 9 10 Next ›