(22.01.) Type IIB at Eight Derivatives: A Status Report
Raffaele Savelli (Università di Roma "Tor Vergata")
22.01.2026 at 16:15
Knowledge of ten-dimensional superstring effective actions beyond the leading order in the derivative expansion is of intrinsic interest and plays a central role in many questions in string phenomenology. For Type IIB string theory, all the effective couplings are known at the four-point level, but a complete characterization of the eight-derivative effective action remains elusive. In this seminar, I will discuss recent progress in deriving the five-point contact terms in sectors that mix gravity with the three-form flux and the axio-dilaton. I will present different approaches to this problem and emphasize the role of SL(2,Z) duality in constraining the structure of eight-derivative couplings and in revealing universal kinematical patterns. Finally, I will briefly comment on applications to lower-dimensional physics.
The talk is based on arXiv:2205.11530 and arXiv:2507.07934.
A348