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In this paper, we develop a domain decomposition method for the nonlinear Poisson-Boltzmann equation based on a solvent-excluded surface widely used in computational chemistry. The model relies on a nonlinear equation defined in…

数值分析 · 数学 2024-04-08 Abhinav Jha , Benjamin Stamm

Einstein originally proposed a nonsymmetric tensor field, with its symmetric part associated with the spacetime metric and its antisymmetric part associated with the electromagnetic field, as an approach to a unified field theory. Here we…

广义相对论与量子宇宙学 · 物理学 2018-03-14 J. R. van Meter

Although cosmological solutions to Einstein's equations are known to be generically singular, little is known about the nature of singularities in typical spacetimes. It is shown here how the operator splitting used in a particular…

广义相对论与量子宇宙学 · 物理学 2009-10-22 B. K. Berger , V. Moncrief

We present novel classes of non-stationary solutions to the five-dimensional generalized Einstein-Maxwell-dilaton theory with cosmological constant, in which the Maxwell's filed and the cosmological constant couple to the dilaton field. In…

高能物理 - 理论 · 物理学 2019-05-29 Michael Butler , A. Masoud Ghezelbash

We consider nonlinear redshift-dependent equation of state parameters as dark energy models in a spatially flat Friedmann-Lema\^itre-Robertson-Walker universe. To depict the expansion history of the universe in such cosmological scenarios,…

广义相对论与量子宇宙学 · 物理学 2018-02-06 Weiqiang Yang , Supriya Pan , Andronikos Paliathanasis

In this thesis we investigate cosmological models more general than the isotropic and homogeneous Friedmann-Lemaitre models. We focus on cosmologies with one spatial degree of freedom, whose matter content consists of a perfect fluid and…

广义相对论与量子宇宙学 · 物理学 2009-09-29 Woei Chet Lim

The sensitivity limits of space telescopes are imposed by uncalibrated errors in the point spread function, photon-noise, background light, and detector sensitivity. These are typically calibrated with specialized wavefront sensor hardware…

天体物理仪器与方法 · 物理学 2024-06-18 Louis Desdoigts , Benjamin Pope , Jordan Dennis , Peter Tuthill

We describe the implementation of a new approach to the numerical evaluation of the effects of non-cold relics on the evolution of cosmological perturbations. The Boltzmann hierarchies used to compute the contributions of these relics to…

宇宙学与河外天体物理 · 物理学 2025-09-03 Nanoom Lee , José Luis Bernal , Sven Günther , Lingyuan Ji , Marc Kamionkowski

We present CosmoPower-JAX, a JAX-based implementation of the CosmoPower framework, which accelerates cosmological inference by building neural emulators of cosmological power spectra. We show how, using the automatic differentiation, batch…

宇宙学与河外天体物理 · 物理学 2023-06-27 D. Piras , A. Spurio Mancini

We present a new flexible, fast and accurate way to implement massive neutrinos, warm dark matter and any other non-cold dark matter relics in Boltzmann codes. For whatever analytical or numerical form of the phase-space distribution…

宇宙学与河外天体物理 · 物理学 2015-10-14 Julien Lesgourgues , Thomas Tram

We present a significantly improved version of our numerical code JASMINE, that can now solve the Jeans equations for axisymmetric models of stellar systems, composed of an arbitrary number of stellar populations, a Dark Matter halo, and a…

星系天体物理 · 物理学 2020-03-18 Caterina Caravita , Luca Ciotti , Silvia Pellegrini

We consider a spatially homogeneous and isotropic cosmological model where Dirac spinors are coupled to classical gravity. For the Dirac spinors we choose a Hartree-Fock ansatz where all one-particle wave functions are coherent and have the…

数学物理 · 物理学 2014-04-23 Felix Finster , Christian Hainzl

We study the phase space dynamics of cosmological models in the theoretical formulations of non-minimal metric-torsion couplings with a scalar field, and investigate in particular the critical points which yield stable solutions exhibiting…

广义相对论与量子宇宙学 · 物理学 2017-08-18 Arshdeep Singh Bhatia , Sourav Sur

The dark energy formula derived by Gurzadyan and Xue which leads to a value fitting the SN data, provides a scaling relation between the physical constants and cosmological parameters and defines a set of cosmological models. In previous…

天体物理学 · 物理学 2014-10-13 G. V. Vereshchagin , G. Yegorian

The numerical solution of partial differential equations is at the heart of many grand challenges in supercomputing. Solvers based on high-order discontinuous Galerkin (DG) discretisation have been shown to scale on large supercomputers…

数学软件 · 计算机科学 2020-11-12 Carsten Uphoff , Michael Bader

We present a general solution of the coupled Einstein-Maxwell field equations (without the source charges and currents) in three spacetime dimensions. We also admit any value of the cosmological constant. The whole family of such…

广义相对论与量子宇宙学 · 物理学 2022-08-23 Jiri Podolsky , Matus Papajcik

This is Part II of the paper series on data-compatible T-matrix completion (DCTMC), which is a method for solving nonlinear inverse problems. Part I of the series contains theory and here we present simulations for inverse scattering of…

数学物理 · 物理学 2016-11-02 Howard W. Levinson , Vadim A. Markel

A quantum cosmological model with radiation and a dilaton scalar field is analysed. The Wheeler-deWitt equation in the mini-superspace induces a Schr\"odinger equation, which can be solved. An explicit wavepacket is constructed for a…

广义相对论与量子宇宙学 · 物理学 2015-06-11 J. C. Fabris , F. T. Falciano , P. Vargas Moniz , J. Marto , N. Pinto-Neto

The ultimate application of Einstein's field equations is to empirically determine the geometry of the Universe from its matter content, rather than simply assuming the Universe can be represented by a homogeneous model on all scales.…

广义相对论与量子宇宙学 · 物理学 2008-11-26 M. L. McClure , Charles Hellaby

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…

宇宙学与河外天体物理 · 物理学 2023-07-13 L. Arturo Ureña-López , Francisco X. Linares Cedeño