Notes on Matrix and Micro Strings
R. Dijkgraaf, E. Verlinde, H. Verlinde
TL;DR
This work surveys Matrix theory approaches to M-theory compactifications, with a focus on M-theory on T^5 and the emergence of IIA/IIB strings together with the M5-brane. It develops a 5+1D worldvolume (2,0) tensor multiplet on an auxiliary tilde{T}^5 and a dual micro-string theory whose T-duality renders U-duality manifest for BPS spectra. By connecting NS5-brane matrix descriptions, SYM on T^5, and matrix string theory, the authors show how the 16 central charges of M-theory arise as fluxes and how winding micro-strings organize the spectrum and interactions via twist-field dynamics. They further advance a second-quantized, S_N orbifold framework to describe string interactions and propose a rich web of dualities and moduli-space structures, including instanton moduli spaces and potential 4D extensions, with implications for black hole microphysics and duality symmetries.
Abstract
We review some recent developments in the study of M-theory compactifications via Matrix theory. In particular we highlight the appearance of IIA strings and their interactions, and explain the unifying role of the M-theory five-brane for describing the spectrum of the T^5 compactification and its duality symmetries. The 5+1-dimensional micro-string theory that lives on the fivebrane world-volume takes a central place in this presentation.