# Scalar boundary condition in background with U(1) isometry

• A

## Main Question or Discussion Point

I have a simple question about Lewkowycz and Maldacena's paper [PLAIN]http://arxiv.org/abs/1304.4926v2[/PLAIN] [Broken]
http://arxiv.org/abs/1304.4926v2

In section 2, they consider the scalar field in BTZ background ground and require boundary condition of the scalar field,

$\phi \sim e^{i\tau}$ . This boudary condition breaks the U(1) isomentry of BTZ background. My question is what kinds of boudary condition will respect the U(1) isometry? $\phi$does not depend on $\tau$?

Last edited by a moderator:

Related Special and General Relativity News on Phys.org
Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

The answer is YES. Respecting U(1) symmetry of phi means independence of tau coordinate.