TH String Theory Seminar

M-strings and Little Strings

by Stefan Hohenegger (IPNL Lyon)

Europe/Zurich
4/2-011 - TH common room (CERN)

4/2-011 - TH common room

CERN

15
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Description
I study BPS excitations in M5-M2-brane configurations with a compact transverse direction, which are also relevant for type IIa and IIb little string theories. These configurations are dual to a class of toric elliptically fibered Calabi-Yau manifolds $X_N$ with manifest $SL(2,\mathbb{Z})\times SL(2,\mathbb{Z})$ modular symmetry. They admit two dual gauge theory descriptions. For both, the non-perturbative partition function can be written as an expansion of the topological string partition function of $X_N$ with respect to either of the two modular parameters. I analyse the resulting BPS counting functions in detail and unravel a number of remarkable relations. In particular, I find that for certain M2-brane configurations, the free energies in the two dual theories agree with each other. This points to a new correspondence between instanton and monopole configurations and is also a manifestation of T-duality between type IIa and IIb little string theories. Finally, I briefly comment on a generalisation of these results to little string orbifolds.