## – Europe/Lisbon

— Online

Inder Kaur, Goethe University Frankfurt am Main*To be announced*

Geometria em Lisboa Seminar

— Online

Inder Kaur, Goethe University Frankfurt am Main*To be announced*

— Online

Vinicius Ramos, Instituto de Matemática Pura e Aplicada*To be announced*

Room P3.10, Mathematics Building — Online

Michael Albanese, Université du Québec à Montréal

The Yamabe Invariant of Complex Surfaces

The Yamabe invariant is a real-valued diffeomorphism invariant coming from Riemannian geometry. Using Seiberg-Witten theory, LeBrun showed that the sign of the Yamabe invariant of a Kähler surface is determined by its Kodaira dimension. We consider the extent to which this remains true when the Kähler hypothesis is removed. This is joint work with Claude LeBrun.

Room P3.10, Mathematics Building — Online

Aleksandar Milivojevic, Max Planck Institute for Mathematics - Bonn*To be announced*

Room P3.10, Mathematics Building — Online

Bruno de Oliveira, University of Miami*To be announced*

Room P3.10, Mathematics Building — Online

Alexander Givental, University of Berkeley

K-theoretic Gromov-Witten invariants and their adelic characterization

Gromov-Witten invariants of a given Kahler target space are defined as suitable intersection numbers in moduli spaces of stable maps of complex curves into the target space. Their K-theoretic analogues are defined as holomorphic Euler characteristics of suitable vector bundles over these moduli spaces.

We will describe how the Kawasaki-Riemann-Roch theorem expressing holomorphic Euler characteristics in cohomological terms leads to the adelic formulas for generating functions encoding K-theoretic Gromov-Witten invariants.