<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Il giorno<b> martedì 31 ottobre </b><div>alle ore<b> 16,30 </b>in aula Beltrami </div><div>(notate giorno e ora non standard!)</div><div><br></div><div>il dottor Giancalro Urzuà (Pontificia Universidad Catolica de Chile)<br><br>terrà un seminario dal titolo: Boundedness for T-singularities in KSBA surfaces and the Horikawa’s problem</div><div><br><br>T-singularities, defined by Kollár–Shepherd-Barron 1988, are the 2-dimensional quotient singularities that admit a smoothing with constant K^2. These singularities are relevant in the Kollár–Shepherd-Barron-Alexeev (KSBA) compactification of the moduli space of surfaces of general type. In a recent joint project (https://arxiv.org/abs/2308.05624) with Fernando Figueroa (PhD student at Princeton University) and Julie Rana (Lawrence University), we effectively bound T-singularities on non-rational projective surfaces W with an arbitrary amount of T-singularities, and K_W ample. This generalizes a previous work together with Julie (https://arxiv.org/abs/1708.02278), passing from 1 to arbitrarily many singularities. We classify all possible geometric situations for which our bound is higher than expected. I will talk about this new paper and future applications on the famous problem about diffeo type of certain Horikawa surfaces.<br><br><br>Tutti gli interessati sono invitati a partecipare.</div><div>Chi vuole venire a cena dopo mi scriva.</div><div><div>
-----------------------<br><br><br>Lidia Stoppino<br>Dipartimento di Matematica<br>Università di Pavia<br>Via Ferrata 5<br>27100 Pavia<br>Ufficio C.07 (primo piano)<br>Tel. +39 0382 985624<br>e-mail: lidia.stoppino@unipv.it <br>pagina web: http://www.stoppino.it<br><br><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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