Conservation Laws in Gravitation and Cosmology

TL;DR

This paper reviews the role of conservation laws in gravitation and cosmology, discusses their generalization in curved spacetime, and explores Rastall's modified gravity theory with applications to cosmology.

Contribution

It analyzes the implementation of conservation laws in General Relativity and investigates Rastall's gravity as a novel approach with cosmological applications.

Findings

Rastall's theory can produce results comparable to the Standard Cosmological Model

Challenges exist in extending conservation laws to curved spacetime

Rastall's modification offers alternative explanations in cosmology

Abstract

The existence of conservation laws is one of the most important requirement of physical theories. Some of them, like energy conservation, knows no experimental exception. However, the generalization of these conservation laws to curved space presents many challenges. The implementation of conservation laws in the General Relativity theory is revised, and the possibility of the generalization of the usual expression is discussed. The Rastall's theory of gravity, which considers a modification of the usual conservation of the energy-momentum tensor, is discussed in more detail. Some applications of the Rastall's theory to cosmology are presented, showing that it can lead to competetive results with respect to the Standard Cosmological Model.