Título: Blown-up toric surfaces with non-polyhedral effective cone

Palestrante: Ana-Maria Castravet - Université Paris-Saclay, UVSQ
Data: 13/10/2020
Horário: 14:00 GMT (11h BRT)
Local: Transmissão online

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Resumo: I will report on recent joint work with Antonio Laface, Jenia Tevelev and Luca Ugaglia. We construct examples of projective toric surfaces whose blow-up at a general point has a non-polyhedral pseudoeffective cone, both in characteristic 0 and in prime characteristic. As a consequence, we prove that the pseudo-effective cone of the Grothendieck-Knudsen moduli space of stable, n-pointed, rational stable curves, is not polyhedral if n>=10 in characteristic 0 and in positive characteristic for an infinite set of primes of positive density. In particular, these moduli spaces are not Mori dream spaces even in positive characteristic.

Host: Ivan Cheltsov
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