Large N

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.