We consider D-branes in group manifolds, from the point of view of open
strings and using the Born-Infeld action on the brane worldvolume. D-branes
correspond to certain integral (twined) conjugacy classes. We explain the
integrality condition on the conjugacy classes in both approaches. In the
Born-Infeld description, the D-brane worldvolume is stabilized against
shrinking by a subtle interplay of quantized U(1) fluxes and the non-triviality
of the B-field.Comment: 6 pages. Invited talk at the 9th Marcel Grossmann meeting, Rome, July
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