Slice Energy and Theories of Gravitation

TL;DR

This paper reviews the use of slice energy in generalized gravitation theories, emphasizing energy exchange mechanisms and the invariance of slice energy properties under conformal transformations.

Contribution

It demonstrates that slice energy can be consistently defined across conformally-related theories, regardless of the frame, highlighting their physical equivalence.

Findings

Slice energy is definable in all conformally-related gravitation theories.

Properties of slice energy are invariant under conformal transformations.

The energy exchange between matter and scalar fields is characterized in these theories.

Abstract

We review recent work on the use of the slice energy concept in generalized theories of gravitation. We focus on two special features in these theories, namely, the energy exchange between the matter component and the scalar field generated by the conformal transformation to the Einstein frame of such theories and the issue of the physical equivalence of different conformal frame representations. We show that all such conformally-related, generalized theories of gravitation allow for the slice energy to be invariably defined and its fundamental properties be insensitive to conformal transformations.