Remarks on D_p and D_{p-2} with each carrying a flux

TL;DR

This paper investigates the interactions between Dp and Dp-2 branes with fluxes, revealing new features like repulsive forces and enhanced pair production rates, extending understanding beyond the fluxless or equal-dimensional cases.

Contribution

It provides a detailed analysis of Dp-Dp-2 brane interactions with fluxes, uncovering novel behaviors such as repulsive interactions and conditions for enhanced open string pair production.

Findings

Interaction can be repulsive under certain flux conditions.

No tachyonic instability occurs in some flux configurations.

Exponential enhancement of open string pair production rate.

Abstract

We explore various properties of interaction between D$_p$ and D$_{p'}$ with each carrying a worldvolume flux and with the $p'$-branes placed along $p'$ spatial worldvolume directions of the p-branes at a separation when $p - p' = 2$. Carefully analyzing the annulus amplitudes calculated via the boundary state approach, we find that many features of amplitudes remain similar to those studied when $p = p'$ such as the nature of force on the brane separation, the onset of various instabilities when the brane-separation is on the order of string scale and the occurrence of pair production of open strings when there is a relevant electric flux present. In addition, we have also found many new features of interaction which don't appear in the absence of fluxes or when $p = p'$ in the presence of fluxes, for examples, the nature of interaction can be repulsive and there is no onset of tachyonic instability under certain conditions. Even in the absence of a magnetic flux, we can have an exponential enhancement of the rate of pair production of open strings in certain cases, which may be significant enough to give observational consequences.