Closed string radiation from the interacting fractional-dressed Dp-branes with the transverse motions

Abstract

We determine the boundary states, associated with a fractional Dp-brane in the presence of the Kalb–Ramond field and a U(1) gauge potential. The background spacetime is the non-compact orbifold $$ {\mathbb {R}}^{1, 21} \otimes {\mathbb {R}}^4/ {\mathbb {Z}}_2$$ R 1 , 21 ⊗ R 4 / Z 2 . Besides, the brane has a transverse velocity. We compute the radiation amplitude of a massless closed string from the interaction of two fractional Dp-branes with the previous background fields. The branes have been dressed by different fields and have transverse motions. The total radiation amplitude will be investigated for large inter-brane separation. Finally, the graviton, Kalb–Ramond (axion) and dilaton emissions will be distinctly studied. Our calculations are in the context of the bosonic string theory.