Welschinger-Witt invariants. (Jonannes Rau, Universidad de los Andes)

24.03.2025 14:00 – 16:00

Abstract:
The "quadratically enriched" invariants defined by
Kass-Levine-Solomon-Wickelgren are obtained by counting rational curves
over an arbitrary ground field and take values in the associated
Witt-ring of quadratic forms. Specializing these values to rank and
signature reproduces the corresponding Gromov-Witten and Welschinger
invariants, respectively. In my talk, I want to introduce the concept of
a Witt invariant which can be computed in terms of multiquadratic and
multireal field extensions. We will see that Welschinger invariants give
naturally rise to such an Witt invariant which in some cases
(conjecturally always) coincides with the quadratically enriched invariants.

Lieu

Bâtiment: Conseil Général 7-9

Room 6-13, Geneva-Neuchatel Symplectic seminar (GeNeSys)

entrée libre