Understanding the structure of the D1–D5 CFT and computing its CFT data are important and challenging problems in the study of the AdS3/CFT2 correspondence. We make progress on these questions by studying string amplitudes in AdS spacetime using a combination of CFT and worldsheet techniques. More specifically, we compute the first curvature correction to the four-point string amplitude of arbitrary Kaluza–Klein (KK) modes on AdS3 × S3 × M4, with M4 = K3 or T4, in type IIB string theory, and relate it via AdS/CFT to the corresponding four-point functions of tensor operators in the dual D1–D5 CFT. The result admits an integral representation over the Riemann sphere, directly analogous to the flat-space Virasoro–Shapiro amplitude, but with insertions of weight-three single-valued multiple polylogarithms that capture the leading curvature correction. Our derivation makes full use of the AdS × S Mellin formalism, together with consistency constraints from the flat-space, CFT, and supergravity limits. On this basis, we extract extensive strong-coupling CFT data for the D1–D5 CFT, including anomalous dimensions and OPE coefficients for infinite families of operators. This provides analytic input for future studies and for comparison with complementary approaches such as integrability.

Biography

Hongliang Jiang is currently an Associate Professor at the Shanghai Institute for Mathematics and Interdisciplinary Sciences and at Fudan University. He received his Ph.D. from the Hong Kong University of Science and Technology in 2018. He subsequently held postdoctoral positions at the University of Bern, Queen Mary University of London, and Imperial College London. His research interests lie in theoretical and mathematical physics, with a focus on advancing the understanding of quantum field theory and quantum gravity.

Inviter: Jie-Qiang Wu