Heterotic versus Type I
High Energy Physics - Theory
2009-10-30 v2
Abstract
I compare the calculations of special and terms in the (toroidally-compactified) heterotic and type-I effective actions. Besides checking duality, this elucidates the quantitative rules of D-brane calculus. I explain in particular (a) why D-branes do not run in loops, and (b) how their instanton contributions arise from orbifold fixed points of their moduli space. The instanton sum has a simple representation as a sum of the elliptic genera of matrix models.
Cite
@article{arxiv.hep-th/9710102,
title = {Heterotic versus Type I},
author = {C. Bachas},
journal= {arXiv preprint arXiv:hep-th/9710102},
year = {2009}
}
Comments
7 pages, Latex, one figure, uses espcrc2.sty, Talk at STRINGS'97 (Amsterdam, June 16-21) and HEP-97 (Jerusalem, August 19-26). A misprint in an equation was corrected