Brane couplings from bulk loops

We compute loop corrections to the effective action of a field theory on a five-dimensional S-1/Z(2) orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings. (C) 2001 Published by Elsevier Science B.V.