Large N

TL;DR

This paper reviews recent lattice results on the large-N limit of SU(N) gauge theories in 3+1 dimensions, highlighting confinement, string stability, and related phenomena, and discusses their implications for understanding strong interactions.

Contribution

It provides an overview of lattice calculations that shed light on the properties of SU(N) gauge theories as N approaches infinity, connecting to theoretical simplifications and dualities.

Findings

SU(∞) closely approximates SU(3) in certain features

Discovery of new stable strings at larger N

Insights into confinement and deconfinement phenomena

Abstract

Some mysterious features of the strong interactions become easily understood if our usual QCD with N=3 is `close to' SU(oo) and if the latter theory is confining. N=oo theories are theoretically simpler; in particular there has been much progress in constructing weak-coupling duals in string theory. In this poster I will describe some of the things that recent lattice calculations tell us about the large-N limit of SU(N) gauge theories in 3+1 dimensions. The focus is on confinement, how close SU(oo) is to SU(3), new stable strings at larger N, the Pomeron, deconfinement, topology, 't Hooft string tensions. I also allude to other topics, such as the high-T pressure deficit, chiral physics and the phases of the theory.