5 research outputs found
On the BPS Spectrum at the Root of the Higgs Branch
We study the BPS spectrum and walls of marginal stability of the
supersymmetric theory in four dimensions with gauge group SU(n)
and fundamental flavours at the root of the Higgs branch. The
strong-coupling spectrum of this theory was conjectured in hep-th/9902134 to
coincide with that of the two-dimensional supersymmetric
sigma model. Using the Kontsevich--Soibelman
wall-crossing formula, we start with the conjectured strong-coupling spectrum
and extrapolate it to all other regions of the moduli space. In the
weak-coupling regime, our results precisely agree with the semiclassical
analysis of hep-th/9902134: in addition to the usual dyons, quarks, and
bosons, if the complex masses obey a particular inequality, the resulting
weak-coupling spectrum includes a tower of bound states consisting of a dyon
and one or more quarks. In the special case of -symmetric
masses, there are bound states with one quark for odd and no bound states
for even .Comment: 11 pages, 4 figure
Wall Crossing and Instantons in Compactified Gauge Theory
We calculate the leading weak-coupling instanton contribution to the
moduli-space metric of N=2 supersymmetric Yang-Mills theory with gauge group
SU(2) compactified on R^3 x S^1. The results are in precise agreement with the
semiclassical expansion of the exact metric recently conjectured by Gaiotto,
Moore and Neitzke based on considerations related to wall-crossing in the
corresponding four-dimensional theory.Comment: 24 pages, no figure
Moduli Space and Wall-Crossing Formulae in Higher-Rank Gauge Theories
We study the interplay between wall-crossing in four-dimensional gauge theory
and instanton contributions to the moduli space metric of the same theory on
. We consider SUSY Yang--Mills with
gauge group SU(n) and focus on walls of marginal stability which extend to weak
coupling. By comparison with explicit field theory results we verify the
Kontsevich--Soibelman formula for the change in the BPS spectrum at these walls
and check the smoothness of the metric in the corresponding compactified
theory. We also verify in detail the predictions for the one instanton
contribution to the metric coming from the non-linear integral equations of
Gaiotto, Moore and Nietzke.Comment: 26 pages, no figure