Electromagnetic String Fluid in Rolling Tachyon

TL;DR

This paper investigates the dynamics of a rolling tachyon in an unstable D3-brane system with electromagnetic fields, revealing a fluid-like behavior of string-like objects influenced by electric and magnetic fields.

Contribution

It provides a comprehensive analysis of homogeneous solutions with electromagnetic fields in the Born-Infeld action and interprets fluctuations as a string fluid with specific directional properties.

Findings

Identified homogeneous solutions with constant electric and magnetic fields.

Fluctuations suggest a string fluid with electric and magnetic field characteristics.

Propagating waves align with string directions, moving perpendicular to the tachyon roll.

Abstract

We study Born-Infeld type effective action for unstable D3-brane system including a tachyon and an Abelian gauge field, and find the rolling tachyon with constant electric and magnetic fields as the most general homogeneous solution. Tachyonic vacua are characterized by magnitudes of the electric and magnetic fields and the angle between them. Analysis of small fluctuations in this background shows that the obtained configuration may be interpreted as a fluid consisting of string-like objects carrying electric and magnetic fields. They are stretched along one direction and the rolling tachyon move in a perpendicular direction to the strings. Direction of the propagating waves coincides with that of strings with velocity equal to electric field.