research

Matching the (DR4)-R-6 interaction at two-loops

Abstract

The coefficient of the D6R4D^6 {\cal R}^4 interaction in the low energy expansion of the two-loop four-graviton amplitude in type II superstring theory is known to be proportional to the integral of the Zhang-Kawazumi (ZK) invariant over the moduli space of genus-two Riemann surfaces. We demonstrate that the ZK invariant is an eigenfunction with eigenvalue 5 of the Laplace-Beltrami operator in the interior of moduli space. Exploiting this result, we evaluate the integral of the ZK invariant explicitly, finding agreement with the value of the two-loop D6R4D^6 {\cal R}^4 interaction predicted on the basis of S-duality and supersymmetry. A review of the current understanding of the D2pR4D^{2p} {\cal R}^4 interactions in type II superstring theory compactified on a torus TdT^d with p3p \leq 3 and d4d \leq 4 is included.Comment: 40 pages, various typos and coefficients corrected in version

    Similar works