Dissertation/Thesis Abstract

An Elastic Constitutive Model of Spacetime and Its Applications
by Tenev, Tichomir G., Ph.D., Mississippi State University, 2018, 225; 10978458
Abstract (Summary)

We introduce an elastic constitutive model of gravity that enables the interpretation of cosmological observations in terms of established ideas from Solid Mechanics and multi-scale modeling. The behavior of physical space is identified with that of a material-like medium called "cosmic fabric," which exhibits constitutive behavior. This cosmic fabric is a solid hyperplate that is broad in the three ordinary spatial dimensions and thin in a fourth hyperspatial dimension. Matter in space is treated as fabric inclusions that prescribe in-plane (three-dimensional) strain causing the transverse bending of the fabric into the fourth hyperspatial dimension. The linearized Einstein-Hilbert action, which governs the dynamics of physical space, is derived from postulating Hooke's Law for the fabric, and the Schwarzschild metric is recovered from investigating matter-fabric interactions. At the continuum length scale, the Principle of Relativity is shown to apply for both moving and stationary observers alike, so that the fabric's rest reference frame remains observationally indistinguishable at such a length scale. Within the Cosmic Fabric paradigm, the structural properties of space at different hierarchical length scales can be investigated using theoretical notions and computational tools from solid mechanics to address outstanding problems in cosmology and fundamental physics. For example, we propose and offer theoretical support for the "Inherent Structure Hypothesis", which states that the gravitational anomalies currently attributed to dark matter may in fact be manifestations of the inherent (undeformed) curvature of space. In addition, we develop a numerical framework wherein one can perform numerical "experiments" to investigate the implications of said hypothesis.

Indexing (document details)
Advisor: Horstemeyer, Mark F.
Commitee: Haupt, Tomasz A., Wang, Anzhong, Yarahmadian, Shantia
School: Mississippi State University
Department: Computational Engineering
School Location: United States -- Mississippi
Source: DAI-B 80/05(E), Dissertation Abstracts International
Subjects: Computational physics, Mechanical engineering, Astrophysics
Keywords: Constitutive model, Cosmic fabric, Dark matter, Hierarchical length scales, Modified gravity, Spacetime
Publication Number: 10978458
ISBN: 9780438758490
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