Tube of (Circle F, D0, D2) Bound State in Melvin Background

TL;DR

This paper demonstrates that fundamental strings, D2-branes, and D0-branes can form stable tubular bound states in a Melvin background, with stability depending on their charge ratios, differing from known angular momentum-supported tubes.

Contribution

It introduces a new type of tubular bound state stabilized by magnetic forces in Melvin backgrounds, distinct from angular momentum-supported configurations.

Findings

Stable tubular bound states exist in Melvin backgrounds.

Critical charge ratios determine stability and collapse.

Configurations differ from known angular momentum-supported tubes.

Abstract

By using the Born-Infeld action we show that the $m$ circular fundamental strings, $n$ D2-branes and $k$ D0-branes could become a tubular bound state which is prevented from collapsing by the magnetic force in the Melvin background. However, if the ratio $m/n$ is larger then a critical value the tube will become unstable and collapse to zero radius. We make analyses to find the critical value and tube radius therein. The tube configurations we found are different from the well known tubular bound states of straight fundamental strings, D0 and D2-branes, which are supported by the angular momentum.