Does a Nambu-Goto wall emit gravitational waves? -- Cylindrical Nambu-Goto wall as an example of gravitating non-spherical walls --

TL;DR

This paper investigates whether cylindrical Nambu-Goto walls emit gravitational waves, showing that their motion indeed produces gravitational radiation and affects their dynamics, contrasting with non-gravitating membranes.

Contribution

It demonstrates that gravitating Nambu-Goto walls emit gravitational waves and that gravity suppresses their oscillatory behavior, providing insights into their interaction with gravitational radiation.

Findings

Gravitational waves are emitted by moving cylindrical Nambu-Goto walls.

Neglecting wave emission leads to singular spacetimes.

Gravity reduces the dynamical degrees of freedom of the wall.

Abstract

Gravitational field of a cylindrical Nambu-Goto wall in the vacuum spacetime is considered in order to clarify the interaction between Nambu-Goto membranes and gravitational waves. If one neglects the emission of gravitational waves by the wall motion, the spacetime becomes singular. It is also shown that the emission of gravitational waves does occur by the motion of the cylindrical wall if the initial data is singularity free. The energy loss rate due to radiation of gravitational waves agrees with that estimated from the test wall motion and the quadrupole formula for the gravitational wave emission. This is quite different from the oscillatory behavior of gravitating Nambu-Goto membranes: the presence of gravity induces the wall to lose its dynamical degree of freedom.