%0 Journal Article %T D-branes in Orbifold Singularities and Equivariant K-Theory %A Hugo Garcia-Compean %J Physics %D 1998 %I arXiv %R 10.1016/S0550-3213(99)00270-9 %X The study of brane-antibrane configurations in string theory leads to the understanding of supersymmetric D$p$-branes as the bound states of higher dimensional branes. Configurations of pairs brane-antibrane do admit in a natural way their description in terms of K-theory. We analyze configurations of brane-antibrane at fixed point orbifold singularities in terms of equivariant K-theory as recently suggested by Witten. Type I and IIB fivebranes and small instantons on ALE singularities are described in K-theoretic terms and their relation to Kronheimer-Nakajima construction of instantons is also provided. Finally the D-brane charge formula is reexamined in this context. %U http://arxiv.org/abs/hep-th/9812226v3