Math. Phys. seminar at SISSA

[Emanuele Tuillier Illingworth]

*********************************************
MATHEMATICAL PHYSICS SECTOR
*********************************************


dr. Margarida Melo
Università Roma 3

will hold a seminar on:

"Compactified Picard stacks over Mg,n"


Abstract
Let Picd,g,n be the stack parametrizing degree d line bundles over smooth
curves of genus g with n marked points. In this talk I will give a construction
of smooth and irreducible algebraic stacks yeldying a modular compactification
of Picd,g,n over the moduli stack of n-pointed stable curves, Mg,n.
By this we mean an algebraic stack with a proper (or at least universally
closed) map ontoMg,n, containing Picd,g,n as a dense open substack. These
stacks parametrize what we will call balanced line bundles over n-pointed
quasistable curves, generalizing L. Caporaso's compactification of the universal
degree d Picard variety over Mg. In fact, for n = 0, we just give a
stack theoretical description of Caporaso's compactification and then, following
the lines of Knudsen's construction of Mg,n, we go on by induction
on the number of points.



Thu. 20 November at 15:30 in SISSA lecture room C