Perturbations and scattering of spherically symmetric d-dimensional alpha'-corrected black holes in string theory

We compute the tensorial gravitational perturbations of general spherically symmetric black holes in d dimensions with string{theoretical alpha' corrections. We then study the scattering of minimally coupled massless scalar fields by such black holes. We obtain a general formula for the low frequency absorption cross section for every black hole of this kind, which we apply to known black hole solutions. In each case we compare the results for the absorption cross section with the black hole entropy, obtained through Wald's formula.Fundação para a Ciência e a Tecnologia (FCT)Plurianual CMAT, projeto CERN/FP/116377/201