2007/12/08 by A. Basu, Anirban Basu
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #hep-th
paper · pdf · doi:10.1103/physrevd.77.106004
published as Phys.Rev.D77:106004,2008 · 42 pages, LaTeX
arxiv created 2007/12/08 · openalex publication_date 2008/05/12 · arxiv updated 2009/12/01 · openalex created_date 2021/08/30 · openalex updated_date 2026/07/28
We propose a manifestly U-duality invariant modular form for the D6R4 interaction in the effective action of type IIB string theory compactified on T2. It receives perturbative contributions up to genus three, as well as nonperturbative contributions from D-instantons and (p,q) string instantons wrapping T2. Our construction is based on constraints coming from string perturbation theory, U-duality, the decompactification limit to ten dimensions, and the equality of the perturbative part of the amplitude in type IIA and type IIB string theories. Using duality, parts of the perturbative amplitude are also shown to match exactly the results obtained from 11 dimensional supergravity compactified on T3 at one loop. We also obtain parts of the genus one and genus k amplitudes for the D2kR4 interaction for arbitrary k\ensuremath≥4. We enhance a part of this amplitude to a U-duality invariant modular form.