Blown-up toric surfaces with non-polyhedral effective cone and applications to moduli spaces

Moduli and Algebraic Cycles

31 August 15:00 - 16:00

Ana-Maria Castravet - University of Versailles Saint-Quentin-en-Yvelines

I will discuss recent joint work with Antonio Laface, Jenia Tevelev and Luca Ugaglia, in which we construct examples of projective toric surfaces whose blow-up at a general point has a non-polyhedral (i.e., not finitely generated) cone of effective divisors, both in characteristic 0 and in prime characteristic. As a consequence, the Grothendieck-Knudsen moduli space of stable rational curves with n>=10 markings has a non polyhedral cone of effective divisors.

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John Christian Ottem
University of Oslo
Dan Petersen
Stockholm University
David Rydh
KTH Royal Institute of Technology


Dan Petersen


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