Mathematical Physics and Algebraic Geometry Seminar

Speaker: Hamza Ahmed, Northeastern University

Title: Heterotic Little String Theories and Inequivalent Genus-One Fibrations

Abstract: Little String Theories (LSTs) are 6D Supersymmetric quantum field theories (SQFTs) with an additional physical relation called T-duality. This enables us to arrange them into equivalence classes, where each equivalence class has 6D LSTs that lead to the same 5D effective theory when compactified on a circle. The problem of finding T-dual LSTs can be mapped to the problem of finding inequivalent genus-one fibrations of the same non-compact Calabi-Yau (CY) threefold. For T-dual theories, certain field theory data is expected to match, which then implies certain invariants of inequivalent fibrations. Focusing on theories with 8 supercharges (Heterotic LSTs), we use this geometry-field theory equivalence to study the T-duality landscape, particularly in the case where the genus-one fiber does not have a section, leading to what are called twisted T-dual theories. Based on the excellent agreement we find between the geometry and field theory arguments, we conjecture the existence of a new class of twisted T-duals for which no geometric construction is known.