Least action principle and gravitational double layer

TL;DR

This paper explores how the least action principle can derive key features of gravitational double layers, a phenomenon in higher derivative gravity theories resembling shock waves, highlighting new gravitational effects beyond General Relativity.

Contribution

It demonstrates that the equations governing gravitational double layers can be directly obtained from the least action principle in higher derivative gravity theories.

Findings

Double layers can be interpreted as gravitational shock waves.

Key features of double layer equations are derivable from the least action principle.

The study advances understanding of phenomena absent in General Relativity.

Abstract

The higher derivative gravitational theories exhibit new phenomena absent in General Relativity. One of them is the possible formation of the so called double layer which is the pure gravitational phenomenon and can be interpreted, in a sense, as the gravitational shock wave. In this paper we show how some very important features of the double layer equations of motion can be extracted straight from the least action principle.