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arXiv 2302.09181gr-qcastro-ph.CO
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重构非解析宇宙学不动点的参数空间

Reconstructing the parameter space of non-analytical cosmological fixed points

Santiago García-Serna, J. Bayron Orjuela-Quintana, César A. Valenzuela-Toledo, Hernán Ocampo-Durán

AI总结:

针对各向异性背景下标量场与矢量场耦合的暗能量模型中不动点无法全部解析求解的问题,提出数值重构参数空间的通用方案,并发现无解析表示的加速吸引子。

摘要:

动力系统理论是分析宇宙学模型时广泛使用的技术。在该框架内,描述模型动力学的方程会被改写为无量纲变量,这些变量按照一组自治的一阶微分方程演化。该自治方程组的不动点编码了模型的渐近演化。通常,这些点可以写成变量关于模型参数的解析表达式,从而能够完整刻画相应的参数空间。然而,在某些情况下,彻底的解析处理是不可能的。在这项工作中,我们给出了一个暗能量模型的例子,即在各向异性背景中与矢量场耦合的标量场,其中并非所有不动点都能被解析地找到。随后,我们提出了一种通用方案,可对参数空间进行数值描述。这使我们能够找到系统中没有解析表示的、有趣的加速吸引子。这项工作可作为高度复杂动力系统数值分析的模板。

英文摘要:

Dynamical system theory is a widely used technique in the analysis of cosmological models. Within this framework, the equations describing the dynamics of a model are recast in terms of dimensionless variables, which evolve according to a set of autonomous first-order differential equations. The fixed points of this autonomous set encode the asymptotic evolution of the model. Usually, these points can be written as analytical expressions for the variables in terms of the parameters of the model, which allows a complete characterization of the corresponding parameter space. However, a thoroughly analytical treatment is impossible in some cases. In this work, we give an example of a dark energy model, a scalar field coupled to a vector field in an anisotropic background, where not all the fixed points can be analytically found. Then, we put forward a general scheme that provides a numerical description of the parameter space. This allows us to find interesting accelerated attractors of the system with no analytical representation. This work may serve as a template for the numerical analysis of highly complicated dynamical systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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