Categoria:
Altro (categoria non censita)
Categoria non censita:
Seminario di Geometria
Data e ora inizio evento:
Data e ora fine evento:
Aula:
Altro (Aula esterna al Dipartimento)
Sede:
Dipartimento di Matematica, Università di Roma Tor Vergata
Aula esterna:
Aula D'Antoni
Speaker:
Johannes Rau (Universidad de Los Andes, Bogotà)
An important problem in enumerative geometry is counting rational curves that interpolate a configuration of points on an algebraic surface. Over the complex numbers, the answer does not depend on the configuration of points and is called the Gromov-Witten invariant. In contrast, over the real numbers, this invariance fails. To recover it, Welschinger invented an “sign” rule that gives rise to Welschinger invariants. Recently, Kass, Levine, Solomon, and Wickelgren constructed an invariant over an (almost) arbitrary field. The small “inconvenience” is that these latter invariants are no longer numbers, but quadratic forms. In a current work with Erwan Brugallé and Kirsten Wickelgren, we establish direct relationships between these different types of invariants. In my talk, I want to give an introduction to this topic.
Contatti/Organizzatori:
guidomaria.lido@gmail.com