Dilaton tadpoles and D-brane interactions in compact spaces

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We analyse some physical consequences when supersymmetry is broken by a set of D-branes and/or orientifold planes in Type II string theories. Generically, there are global dilaton tadpoles at the disk level when the transverse space is compact. By taking the toy model of a set of electric charges in a compact space, we discuss two different effects appearing when global tadpoles are not cancelled. On the compact directions a constant term appears that allows to solve the equations of motion. On the non-compact directions Poincaré invariance is broken. We analyse some examples where the Poincaré invariance is broken along the time direction (cosmological models).After that, we discuss how to obtain a finite interaction between D-branes and orientifold planes in the compact space at the supergravity level.