Exact description of D-branes in K-matrix theory

TL;DR

This paper provides an exact framework for describing D-branes within K-matrix theory, demonstrating their construction from unstable D-instantons and deriving their effective actions through fluctuation analysis.

Contribution

It explicitly constructs D-branes as bound states of unstable D-instantons in K-matrix theory and derives their effective actions from fluctuation analysis.

Findings

D-branes can be constructed as bound states of unstable D-instantons

Fluctuations around D-brane solutions reproduce world-volume fields

Effective Dp-brane actions are obtained from matrix theory fluctuations

Abstract

We summarize how to describe D-branes in a matrix theory based on unstable D-instantons, which we call K-matrix theory, and explicity show that D-branes can be constructed as bound states of infinitly many unstable D-instantons. We examine the fluctuations around Dp-brane solutions in the matrix theory and show that they correctly reproduce fields on the Dp-brane world-volume. Plugging them into the action of the matrix theory, we precisely obtain the Dp-brane action as the effective action of the fluctuations.