Speaker
Andreas Gerhardus
(Bonn)
Description
Two-dimensional gauge field theories with N=(2,2) supersymmetry, known
as gauged linear sigma models (GLSM), may be the ultraviolet completion
for a nonlinear sigma model with Calabi-Yau threefold target space. In
this case, it is possible to calculate certain topological properties of
the Calabi-Yau target space within the GLSM. Recently, a relation
between the partition function of the GLSM on the two-sphere and the
Kaehler potential on the quantum exact Kaehler moduli space of the
Calabi-Yau has been conjectured. We exploit this relation for a pair of
non-abelian GLSMs which display both weakly and strongly coupled phases.
The fact that their two-sphere partition functions agree provides
evidence for a duality between the two models.
From a technical point of view the evaluation of the above mentioned
partition function involves the calculation of multidimensional
Mellin-Barnes integrals. We demonstrate in arbitrary dimension how these
integrals are given as sums of Grothendieck residues.
