A note on singular D-branes in group manifolds Original Research Article

We develop the classification and systematic construction of all possible untwisted D-branes in Lie groups of A-D-E series. D-branes are classified according to their positions in the maximal torus. We construct all untwisted singular D-branes by the method of iterative deletion in the Dynkin diagram and count their dimensions, which turn out to be always even numbers.