Rank reduction in orientifolds with discrete B explained
by
Igor Pesando(University of Turin)
→
Europe/Stockholm
CoPS group room (A5:1041)
CoPS group room (A5:1041)
Description
On compact orientifolds in the presence of a non-vanishing discrete
Kalb-Ramond field B, the rank of the gauge group is reduced.
The presence of B induces a field strength in a nontrivial bundle on the
branes.
This field strength is necessary for tadpole cancellation,
implies that the number of branes is left unchanged,
gives an explanation of rank reduction as a reduction à la
Scherk-Schwarz, and
allows the derivation of the normalization of the Moebius amplitude
from first principles.
