Gauge Field Flux Research Articles

Heterotic strings on homogeneous spaces

AbstractWe construct heterotic string backgrounds corresponding to families of homogeneous spaces as exact conformal field theories. They contain left cosets of compact groups by their maximal tori supported by NS‐NS 2‐forms and gauge field fluxes. We give the general formalism and modular‐invariant partition functions, then we consider some examples such as SU (2)/U (1) ~ S2 (already described in a previous paper) and the SU (3)/U(1)2 flag space. As an application we construct new supersymmetric string vacua with magnetic fluxes and a linear dilaton.

A note on D-branes in group manifolds: flux quantisation and D0-charge

We show that a D-brane in a group manifold given by a (twisted) conjugacy class is characterised by a gauge invariant two-form field determined in terms of the matrix of gluing conditions. Using a quantisation argument based on the path integral one obtains the known quantisation condition for the corresponding D-branes. We find no evidence for the existence of a quantised U(1) gauge field flux. We propose an expression for the D0 charge of such D-branes.

'Blowing up' D-branes on non-supersymmetric cycles

In the orbifold limit of K3, one can give exact conformal field theory description of D-branes wrapped on certain non-supersymmetric cycles of K3. We study the effect of switching on the `non-geometric blow up modes' corresponding to anti-symmetric tensor gauge field flux through the 2-cycles on these D-branes. Working to first order in the blow up parameter, we determine the region of the moduli space in which these D-branes are stable. Across the boundary of this region, the D-brane wrapped on the non-supersymmetric cycle decays to a pair of D-branes, each wrapped on a supersymmetric cycle, via a second order phase transition.

An interference effect in the interaction of a quantum charge with a quantum solenoid

It is shown that if a quantum mechanical solenoid is observed to be in a superposition of states with different magnetic fluxes then the intensity of the wave function of a charged particle in a simply connected region outside the solenoid would have a spatial variation, even though the field strength in this region due to each of the flux states is zero. This result is generalized to an arbitrary gauge field. The variation of intensity is determined by the gauge covariant difference between the connections corresponding to the gauge field fluxes.