BSM

Abstract

We show that partition functions of N=2 theories on the squashed 3-sphere can be factorized into pairs of vortex theories defined on the two copies of R^2 x S1, corresponding to the two degeneration limits of the ellipsoid. We comment on how the ellipsoid partition function appears to provide the modular invariant non-perturbative completion of the vortex theory. We conclude with the geometrical engineering of the vortex theory.