**SMS scnews item created by John Enyang at Tue 17 Jul 2012 0907**

Type: Seminar

Distribution: World

Expiry: 21 Jul 2012

**Calendar1: 20 Jul 2012 1205-1255**

**CalLoc1: Carslaw 175**

Auth: enyang@penyang.pc (assumed)

### Algebra Seminar

# Exotic t-structures for two-block Springer fibres

### Nandakumar

###### Friday 17th July, 12:05--12:55pm, Carslaw 175

###### Speaker:

Vinoth Nandakumar (Massachusetts Institute of Technology)

###### Title:

Exotic t-structures for two-block Springer fibres

###### Abstract:

We study the exotic t-structure on the derived category of coherent sheaves on the Springer fibre for a two-block nilpotent. The exotic t-structure has been defined by Bezrukavnikov and Mirkovic for any exact base change of the Springer resolution. Using work of Cautis and Kamnitzer, we construct functors indexed by affine tangles, between categories of coherent sheaves on different two-block Springer fibres. After checking some exactness properties of these functors, we describe the irreducible objects in the heart of the exotic t-structure for the nilpotent of type \((m+n,n)\) and enumerate them by crossingless \((m,m+2n)\) matchings.

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After the seminar we will take the speaker to lunch.

See the Algebra Seminar web page for information about other seminars in the series.

John Enyang John.Enyang@sydney.edu.au