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Related papers: The Cosmic Linear Anisotropy Solving System (CLASS…

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The cosmological principle is a cornerstone of the standard cosmological model. However, recent observations suggest potential deviations from this assumption, hinting at a small anisotropic expansion. Such an expansion can arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Jose L. Palacios-Córdoba , J. Bayron Orjuela-Quintana , Gabriela A. Valencia-Zuñiga , César A. Valenzuela-Toledo

We present a numerical analysis of the cosmological evolution of scalar field dark matter (SFDM) in the Boltzmann code $\texttt{CLASS}$, based on a dynamical system analysis of previous works. We show a detailed study of the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-13 L. Arturo Ureña-López , Francisco X. Linares Cedeño

The linear matter power spectrum is an essential ingredient in all theoretical models for interpreting large-scale-structure observables. Although Boltzmann codes such as CLASS or CAMB are very efficient at computing the linear spectrum,…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-20 Giovanni Aricò , Raul E. Angulo , Matteo Zennaro

The Cosmology Large Angular Scale Surveyor (CLASS) is a four telescope array designed to characterize relic primordial gravitational waves from inflation and the optical depth to reionization through a measurement of the polarized cosmic…

A cosmological multidimensional hydrodynamic code is described and tested. This code is based on modern high-resolution shock-capturing techniques. It can make use of a linear or a parabolic cell reconstruction as well as an approximate…

Astrophysics · Physics 2016-08-15 Vicent Quilis , Jose Ma. Ibanez , Diego Saez

A recent reformulation [1] of the problem of Coulomb gases in the presence of a dynamical dielectric medium showed that finite temperature simulations of such systems can be accomplished on the basis of completely local Hamiltonians on a…

Soft Condensed Matter · Physics 2009-11-11 A. Duncan , R. D. Sedgewick

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

The power spectrum is the most commonly applied summary statistics to extract cosmological information from the observed three-dimensional distribution of galaxies in spectroscopic surveys. We present CLASS-OneLoop, a new numerical tool,…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-28 Dennis Linde , Azadeh Moradinezhad Dizgah , Christian Radermacher , Santiago Casas , Julien Lesgourgues

A new description of the binary fluid problem via the lattice Boltzmann method is presented which highlights the use of the moments in constructing two equilibrium distribution functions. This offers a number of benefits, including better…

Soft Condensed Matter · Physics 2009-11-10 K. Stratford , R. Adhikari , I. Pagonabarraga , J. -C. Desplat

The detailed formulation of loop quantum cosmology with higher order holonomy corrections has been constructed recently in the homogeneous and isotropic spacetime, yet it is important to extend the higher order holonomy corrections to…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Xiao-Jun Yue , Jian-Yang Zhu

We consider anisotropic heat flow with extreme anisotropy, as arises in magnetized plasmas for fusion applications. Such problems pose significant challenges in both obtaining an accurate approximation as well in the construction of an…

Numerical Analysis · Mathematics 2024-12-12 Maria Vasilyeva , Golo A. Wimmer , Ben S. Southworth

A new approximation hierarchy, called the LPSUB$m$ scheme, is described for the coupled cluster method (CCM). It is applicable to systems defined on a regular spatial lattice. We then apply it to two well-studied prototypical (spin-1/2…

Strongly Correlated Electrons · Physics 2011-05-05 R F Bishop , P H Y Li

We introduce a new logotropic model based on a complex scalar field with a logarithmic potential that unifies dark matter and dark energy. The scalar field satisfies a nonlinear wave equation generalizing the Klein-Gordon equation in the…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Pierre-Henri Chavanis

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

We investigate a relativistic cosmological model with background rotation, sourced by a non-perfect fluid with anisotropic stress. A modified version of the CLASS Boltzmann code is employed to perform Monte Carlo Markov Chain analyses…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Micol Benetti , David A. Cook , Saulo Carneiro

We present a novel framework for the development of fourth-order lattice Boltzmann schemes to tackle multidimensional nonlinear systems of conservation laws. As for other numerical schemes for hyperbolic problems, high-order accuracy…

Numerical Analysis · Mathematics 2024-09-11 Thomas Bellotti , Philippe Helluy , Laurent Navoret

We describe the special relativistic extension of the CRONOS code, which has been used for studies of gamma-ray binaries in recent years. The code was designed to be easily adaptable, allowing the user to easily change existing…

High Energy Astrophysical Phenomena · Physics 2021-09-29 David Huber , Ralf Kissmann

We present COSMOCR, a numerical code for the investigation of cosmic ray related studies in computational cosmology. The code follows the diffusive shock acceleration, the mechanical and radiative energy losses and the spatial transport of…

Astrophysics · Physics 2009-11-06 Francesco Miniati

The Cosmological Principle, the combined assumptions of cosmological isotropy and homogeneity, underpins the standard model of Big Bang cosmology with which we interpret astronomical observations. A new test of isotropy over the redshift…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-02 E. O. Zavarygin , J. K. Webb