外旋度量中的扁平星系旋转曲线

IF 3.2 Q2 ASTRONOMY & ASTROPHYSICS
Galaxies Pub Date : 2024-04-24 DOI:10.3390/galaxies12030021
Robin Booth
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引用次数: 0

摘要

我们研究了外时空(永恒)度量和相关的ΣGR 宇宙学模型对星系形成的一些影响,特别是它们的旋转曲线特征。我们展示了该模型中来自多个空间超曲面的累积曲率如何导致泊松方程的改进版本,其中引力势是在四维空间中计算的。利用这种新形式的泊松方程,我们推导出了引力势与发生引力坍缩的均匀气体云径向距离函数的解析表达式。我们表明,这得出的径向速度曲线与通常观测到的星系旋转曲线非常吻合,因此完全解释了以前归因于暗物质的效应。与ΣGR引力势相对应的等效物质密度曲线的表达式也可以推导出来,由此可见,它与著名的纳瓦罗-弗伦克-怀特曲线的形式非常相似。为了进一步说明采用出光度量的后果,我们展示了如何利用松弛求解器求解泊松方程和引力势能的演化,轻松地将该原理纳入大尺度结构演化的粒子网格 N-体模拟中。以下是使用这种模拟模型的例子:(a)大尺度结构的初始演化;(b)引力塌缩气体云形成星系。在这两种情况下,都可以直接观察到三维空间中引力势随着模拟演化的积累,并注意到这与目前假定的暗物质是如何对应的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Flattened Galaxy Rotation Curves in the Exochronous Metric
We examine some of the consequences of the Exochronous (timeless) metric and the associated ΣGR cosmological model for the formation of galaxies, and, in particular, their characteristic rotation curves. We show how the cumulative curvature from the multiple spatial hypersurfaces in this model leads to a modified version of the Poisson equation, in which the gravitational potential is computed over 4D space. Using this new form of the Poisson equation, we derive an analytic expression for gravitational potential as a function of radial distance for a uniform gas cloud undergoing gravitational collapse. We show that this results in a radial velocity profile that provides an excellent fit with commonly observed galaxy rotation curves, and hence fully accounts for the effects previously ascribed to dark matter. An expression can be derived for the equivalent matter density profile corresponding to the ΣGR gravitational potential, from which it is evident that this is very similar in form to the well-known Navarro–Frenk–White profile. As a further illustration of the consequences of adopting the Exochronous metric, we show how the principle can readily be incorporated into particle-mesh N-body simulations of large-scale structure evolution, using a relaxation solver for the solution to the Poisson equation and the evolution of the gravitational potential. Examples of the use of this simulation model are shown for the following cases: (a) the initial evolution of a large-scale structure, and (b) galaxy formation from a gravitationally collapsing gas cloud. In both cases, it is possible to directly visualise the build-up of the gravitational potential in 3D space as the simulation evolves and note how this corresponds to what is currently assumed to be dark matter.
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来源期刊
Galaxies
Galaxies Physics and Astronomy-Astronomy and Astrophysics
CiteScore
4.90
自引率
12.00%
发文量
100
审稿时长
11 weeks
期刊介绍: Es una revista internacional de acceso abierto revisada por pares que proporciona un foro avanzado para estudios relacionados con astronomía, astrofísica y cosmología. Areas temáticas Astronomía Astrofísica Cosmología Astronomía observacional: radio, infrarrojo, óptico, rayos X, neutrino, etc. Ciencia planetaria Equipos y tecnologías de astronomía. Ingeniería Aeroespacial Análisis de datos astronómicos. Astroquímica y Astrobiología. Arqueoastronomía Historia de la astronomía y cosmología. Problemas filosóficos en cosmología.
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