A One Loop Problem of the Matrix Big Bang Model

TL;DR

This paper calculates the one-loop effective action for two D0-branes in a matrix model cosmological background, revealing an instability through a non-vanishing velocity-dependent term not predicted by supergravity.

Contribution

It provides the first computation of the one-loop effective action in this setting, uncovering an unexpected velocity-dependent term indicating potential instability.

Findings

Vanishing static potential between D0-branes

Presence of a complex, non-vanishing $v^2$ term

Indication of instability in the system

Abstract

We compute the one-loop effective action of two D0-branes in the matrix model for a cosmological background, and find vanishing static potential. However, there is a non-vanishing $v^2$ term not predicted in a supergravity calculation. This term is complex and signals an instability of the two D0-brane system, it may also indicate that the matrix model is incorrect.