[geometry-ml:03452] MS seminar at Kavli IPMU -- Alexander Alexandrov and Ugo Bruzzo -- Sep 25, 2018

[Todor Milanov]

Dear all,

I would like to announce the following two Mathematics and String theory seminars at Kavli IPMU

1) Speaker: Alexander Alexandrov (IBS Korea)
Date:	Tue, Sep 25, 2018, 13:15 - 14:45
Place:	Seminar Room A

Title: Open intersection numbers, matrix model, and W-constraints

Abstract: From the seminal papers of Witten and Kontsevich we know that the intersection theory on the moduli spaces of complex curves is described by a tau-function of the KdV integrable hierarchy. Moreover, this tau-function is given by a matrix integral and satisfies the Virasoro constraints. Recently, an open version of this intersection theory was introduced. In my talk I will show that the open version can be described very similar to the closed one, in particular it is given by a tau-function of the integrable hierarchy. 
Moreover, it's W-constraints can be naturally described in terms of two free bosonic fields.

2) Speaker:	Ugo Bruzzo	(SISSA)
Date: Tue, Sep 25, 2018, 15:30 - 17:00
Place: Seminar Room B

Title: The Noether-Lefschetz problem for normal threefolds

Abstract: The classical Noether-Lefschetz theorem states that the very general surface in P3 has Picard number 1. The locus of surfaces with a larger Picard number has a complicated geometry; results obtained in the late 80s characterized its components of small codimension, and proved that it is dense in the space of all surfaces. In this talk I will show how to extend some of these results to surfaces in normal 3-folds. Work in collaboration with A. Grassi and (partly) with A. F. Lopez.



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Todor Eliseev Milanov
Associate Professor 
Kavli IPMU,  Japan

todor.milanov ＠ ipmu.jp