SISSA GEOMETRY SEMINARS

[Ugo Bruzzo]

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SISSA GEOMETRY SEMINARS
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Laurent Gruson (Université de Versailles Saint-Quentin)

Tuesday 22 September, 2 pm, Room 005

Title: The universal Fano 3-fold of genus 12

Abstract: In an unpublished paper dated from 2003, Franck
Melliez describes a birational correspondence between the
universal Fano 3-fold of genus 12 and the quotient space of
the vector space of binary duodecimics modulo GL_2, which
I shall describe in this talk.

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Xavier Roulleau (Université de Poitiers)

Wednesday 23 September, 11 am, Room 136

Title : Bounded negativity and arrangements of elliptic curves.

Abstract : The bounded negativity conjecture was formulated long
ago by the Italian school and is an open problem. This conjecture
is that for any complex surface X, there exists a bound b such that
for any (reduced) curve C on X, the self-intersection C^2 is bigger than b.
The Harbourne H-constant and some variant, the linear H-constant,
have been introduced in order to have a better understanding of the
behavior of the bounded negativity conjecture under blow-ups of a
given surface. In this talk I propose to study the elliptic H-constant
and give particular examples of elliptic curves configurations in the
plane implying that the H-constant of any surface is less or equal to -4.