Massive type IIA string theory cannot be strongly coupled

by Alessandro Tomasiello (Università di Milano-Bicocca)

Tuesday 19 Oct 2010, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

String theory is understood today as a single entity, thanks to the dualities established in the ‘90s. An imperfection in this picture is, however, the issue of the strong coupling limit of the ‘massive’ type IIA theory. We will argue that perhaps this problem does not exist. Namely, we will show explicitly that massive type IIA string theory can never be strongly coupled in a weakly curved region of space-time. We will illustrate this general claim with two classes of massive solutions in AdS4 × CP3, with N = 1 and N = 2 supersymmetry. Both solutions are holographically dual to d = 3 Chern–Simons–matter theories. In both these massive examples, as the rank N of the gauge group is increased, the dilaton initially increases in the same way as in the corresponding massless case; before it can reach the M–theory regime, however, it enters a second regime, in which the dilaton decreases even as N increases. In the N = 2 case, we find supersymmetry–preserving gauge–invariant monopole operators whose mass is independent of N. This predicts the existence of branes which stay light even when the dilaton decreases. We will show that, on the gravity side, these states originate from D2–D0 bound states wrapping the vanishing two–cycle of a conifold singularity that develops at large N.