English
Related papers

Related papers: Doing numerical cosmology with the Cactus code

200 papers

The package CosmoLib is a combination of a cosmological Boltzmann code and a simulation toolkit to forecast the constraints on cosmological parameters from future observations. In this paper we describe the released linear-order part of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-12 Zhiqi Huang

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 the advent of new large galaxy surveys, which will produce enormous datasets with hundreds of millions of objects, new computational techniques are necessary in order to extract from them any two-point statistic, the computational time…

Instrumentation and Methods for Astrophysics · Physics 2013-06-21 David Alonso

Cosmological correlators are fundamental observables in an expanding universe and are highly non-trivial functions even at tree-level. In this work, we uncover novel structures in the space of such tree-level correlators that enable us to…

High Energy Physics - Theory · Physics 2025-03-11 Thomas W. Grimm , Arno Hoefnagels , Mick van Vliet

We give an overview of the status of string cosmology. We explain the motivation for the subject, outline the main problems, and assess some of the proposed solutions. Our focus is on those aspects of cosmology that benefit from the…

High Energy Physics - Theory · Physics 2008-11-26 Liam McAllister , Eva Silverstein

Cosmography represents an important branch of cosmology which aims to describe the universe without the need of postulating \emph{a priori} any particular cosmological model. All quantities of interest are expanded as a Taylor series around…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Peter K. S. Dunsby , Orlando Luongo

At present, there is practically no doubt that general relativity is closely related to gravity. Moreover, after the work of Jacobson, Padmanabhan and others, it became clear that a thermodynamic interpretation of Einstein's relativistic…

General Relativity and Quantum Cosmology · Physics 2024-03-19 Yu. L. Bolotin , V. V. Yanovsky

We extend the treatment of quantum cosmology to a manifold with torsion. We adopt a model of Einstein-Cartan-Sciama-Kibble compatible with the cosmological principle. The universe wavefunction will be subject to a $\mathcal{PT}$-symmetric…

General Relativity and Quantum Cosmology · Physics 2020-12-22 Ammar Kasem , Shaaban Khalil

When exoplanets pass in front of their stars, they imprint a transit signature on the stellar light curve which to date has been assumed to be symmetric in time, owing to the planet being modelled as a circular area occulting the stellar…

Instrumentation and Methods for Astrophysics · Physics 2021-07-01 Kathryn Jones , Néstor Espinoza

Non-singular two and three dimensional string cosmologies are constructed using the exact conformal field theories corresponding to SO(2,1)/SO(1,1) and SO(2,2)/SO(2,1). All semi-classical curvature singularities are canceled in the exact…

High Energy Physics - Theory · Physics 2009-10-31 H. J. de Vega , A. L. Larsen , N. Sanchez

The vector-tensor (VT) theory of gravitation revisited in this article was studied in previous papers, where it was proved that VT works and deserves attention. New observational data and numerical codes have motivated further development…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-11 Roberto Dale , Diego Sáez

Cosmology is a field of physics in which the use of General Relativity theory is indispensable. However, a cosmology based on Newtonian gravity theory for gravity is possible in certain circumstances. The applicability of Newtonian theory…

Space Physics · Physics 2013-12-04 J. C. Fabris , Hermano Velten

Cosmological N-Body simulations are used for a variety of applications. Indeed progress in the study of large scale structures and galaxy formation would have been very limited without this tool. For nearly twenty years the limitations…

Astrophysics · Physics 2010-05-07 J. S. Bagla , Nishikanta Khandai

We propose a new approach for multiverse analysis based on computational complexity, which leads to a new family of "computational" measure factors. By defining a cosmology as a space-time containing a vacuum with specified properties (for…

High Energy Physics - Theory · Physics 2018-04-18 Frederik Denef , Michael R. Douglas , Brian Greene , Claire Zukowski

We present a new, three-dimensional (3D) plotting library with advanced features, and support for standard and enhanced display devices. The library - S2PLOT - is written in C and can be used by C, C++ and FORTRAN programs on GNU/Linux and…

Astrophysics · Physics 2009-11-11 D. G. Barnes , C. J. Fluke , P. D. Bourke , O. T. Parry

Runge-Kutta formulas are some of the workhorses of numerical solving of differential equations. However, they are extremely difficult to generate; the algebra involved can be very complicated indeed. It is now standard, following the work…

Numerical Analysis · Mathematics 2014-02-18 Alasdair McAndrew

We present a new numerical code, PLUTO, for the solution of hypersonic flows in 1, 2 and 3 spatial dimensions and different systems of coordinates. The code provides a multi-physics, multi-algorithm modular environment particularly oriented…

Astrophysics · Physics 2009-11-13 A. Mignone , G. Bodo , S. Massaglia , T. Matsakos , O. Tesileanu , C. Zanni , A. Ferrari

Several dark energy models on the brane are investigated. They are compared with corresponding theories in the frame of 4d Friedmann-Robertson-Walker cosmology. To constrain the parameters of the models considered, recent observational…

General Relativity and Quantum Cosmology · Physics 2015-06-12 A. V. Astashenok , E. Elizalde , J. de Haro , S. D. Odintsov , A. V. Yurov

The ability to harness heterogeneous, dynamically available "Grid" resources is attractive to typically resource-starved computational scientists and engineers, as in principle it can increase, by significant factors, the number of cycles…

Distributed, Parallel, and Cluster Computing · Computer Science 2007-05-23 Gabrielle Allen , David Angulo , Ian Foster , Gerd Lanfermann , Chuang Liu , Thomas Radke , Ed Seidel , John Shalf

Current and upcoming surveys will measure the cosmological parameters with an extremely high accuracy. The primary goal of these observations is to eliminate some of the currently viable cosmological models created to explain the late time…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Savvas Nesseris , Domenico Sapone