Relatore
Roberto Volpato
(Univ. Padova)
Descrizione
I will consider a large class of four dimensional N=4 string models
obtained from compactifications of type II string theory on K3 x T^2
and orbifolds thereof. I will show that the multiplicities of 1/4 BPS
states in such models can be determined (almost) uniquely by imposing some
simple consistency condition. The main ingredient in this derivation is a
careful analysis of the wall crossing phenomenon. These results lead to a
better understanding of the action of discrete groups of symmetries on the
BPS spectrum of K3 string models. This talk is based on joint work with
Natalie Paquette and Max Zimet.
