Fractional D3-branes in diverse backgrounds

In the first part of this article, we find fractional D3-branes supergravity solutions on orientifolded C-2 /Z(2) orbifolds of type-IIB string theory. The one-loop corrected gauge couplings for the symplectic or orthogonal groups living on the D-branes are reproduced on the world-volume of probes. In the second part of the paper, we construct a D3-brane solution on the two-centers Taub-NUT manifold which interpolates between fractional D3-branes in the ALE space limit and a T-dual smeared type-IIA configuration. Then, we lift this configuration to M-theory and comment on the connections with wrapped M5-branes solutions.