[geometry-ml:02943] MS seminar at Kavli IPMU -- Ben Davison (U of Glasgow) -- Apr 10, 2017

[Todor Milanov]

Dear all,

I would like to announce the following Mathematics and String theory seminar at Kavli IPMU:

Speaker:	Ben Davison (U of Glasgow)
Date:	Mon, Apr 10, 2017, 13:15 - 14:45
Place:	Seminar Room A

Title: Cohomological BPS invariants, vanishing cycles and Kac-Moody Lie algebras.

Abstract:  The theory of Donaldson-Thomas invariants associates to a quiver Q with potential W a partition function recording the weight polynomials of the cohomology of moduli stacks of representations built out of the Jacobi algebra associated to Q and W.  This theory is a local model for the category of coherent sheaves on a Calabi-Yau 3-fold.  While the partition function looks wildly infinite, after taking plethystic logarithms and multiplying by (1-q) it becomes a power series with polynomial coefficients - the so-called refined DT invariants.  I will explain how to lift these invariants from polynomials to mixed Hodge structures, via categorification, and how this allows us to define a natural Lie algebra associated to an arbitrary quiver, extending the Kac-Moody Lie algebra of the quiver, that conjecturally is the geometric Yangian defined by Maulik and Okounkov.





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Todor Eliseev Milanov
Associate Professor 
Kavli IPMU,  Japan

todor.milanov ＠ ipmu.jp