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Résumé |
Higher-derivative corrections to D-brane effective actions encode genuinely stringy physics beyond the supergravity approximation. Determining these
corrections systematically has remained a long-standing challenge due to the reduced supersymmetry on the brane worldvolume. In this talk, I present a
unified framework for computing all protected couplings at order (\alpha')^2 on the D3-brane, based on the Schwinger proper-time representation of one-
loop amplitudes in M-theory. The method exploits the propagation of the eleven-dimensional superparticle in an M5-brane background compactified on a
two-torus. I will present the complete D3-brane Lagrangian at (\alpha')^2, and show that the modular structure confirms the conjecture of Green and
Gutperle (2000) from first principles. Along the way, I will discuss the role of D-instanton contributions, and potential applications to the KPV metastability
analysis relevant for de Sitter constructions in Type IIB flux compactifications.
Based on 2205.11530, 2507.07934 with J. Liu, R. Minasian, R. Savelli, and upcoming work with F. Compagnin, M. Kim, S. Schreyer. |
