Entanglement and entropy operator for strings in pp-wave time dependent background

Abstract

In this letter new aspects of string theory propagating in a pp-wave time dependent background with a null singularity are explored. It is shown the appearance of a 2d entanglement entropy dynamically generated by the background. For asymptotically flat observers, the vacuum close to the singularity is unitarily inequivalent to the vacuum at $\tau =-\infty$ and it is shown that the 2d entanglement entropy diverges close to this point. As a consequence, the positive time region is inaccessible for observers in $\tau =-\infty$. For a stationary measure, the vacuum at finite time is seen by those observers as a thermal state and the information loss is encoded as a heat bath of string states.

revtex4, 15 pages, revised version to appear in Physics Letters B

References in corpus (1)

• Matrix Membrane Big Bangs and D-brane Production

Cited by in corpus (3)

• Strings in Horizons, Dissipation and a Possible Interpretation of the Hagedorn Temperature
• String Entanglement and D-branes as Pure States
• Observer dependent D-brane for strings propagating in pp-wave time dependent background