Standard model on D-branes

摘要

I brie???y outline previous work on getting the (supersymmetric) standard model from string theory, and then describe two ecent attempts using D-branes. The ???rst uses D3- and D7- branes and gives a supersymmetric standard model with extra vector-like matter and an intermediate uni???cation scale. The second uses intersecting D4-branes and yields a non-supersymmetric spectrum with TeV-scale uni???cation.