D-Branes on the Null-Brane

TL;DR

This paper investigates D-branes in the null-brane background, constructing boundary states via covariant worldsheet formalism, revealing time-dependent tensions for certain D-brane configurations.

Contribution

It introduces a covariant formalism for D-branes on the null-brane and explicitly constructs boundary states in this background.

Findings

D-branes with codimension zero or two exhibit time-dependent effective tensions.

Boundary states for D-branes on the null-brane are explicitly constructed.

The study advances understanding of D-brane dynamics in time-dependent backgrounds.

Abstract

We study D-branes in the null-brane background. Using the covariant formalism of the worldsheet theory, we construct the boundary states describing D-branes on the null-brane. From the cylinder amplitudes, we find that the D-branes with codimension zero or two have time-dependent effective tensions.