Theory SEMINAR

Friday, July 14th, 14:30

Aula Seminari - A-34

S.V. Ketov

Institute for Theoretical Physics,

University of Hannover, Germany

Superconformal Hypermultiplets and ALF Metrics

Abstract:

The manifestly N=2 supersymmetric, off-shell, harmonic

superspace approach is used to solve the constraints implied by

four-dimensional N=2 superconformal smmetry on the N=2 non-linear

sigma-model target space, known as the special hyper-K\"ahler geometry.

The general solution is formulated in terms of a homogeneous (of degree

two) function of unconstrained (analytic) Fayet-Sohnius hypermultiplet

superfields. The improved (N=2 superconformal) actions for the off-shell

(constrained) N=2 projective hypermultiplets are derived and related to

the asymptotically locally-flat (ALF) $A_k$ and $D_k$ series of the

gravitational instantons. These metrics describe Kaluza-Klein monopoles

in M-theory, while they also arise in the quantum moduli spaces of N=4

supersymmetric gauge field theories with $SU(2)$ gauge group and matter

hypermultiplets in three spacetime dimensions.