## Colloquium

##### Thursday, October 23, 2014 at 3:30p.m.

**Amin Gholampour** (*University of Maryland*)

**Abstract:**We explain how toric methods can be used to explore the geometry of moduli spaces of coherent sheaves. In particular, we review the methods of getting combinatorial expressions for Euler characteristics and Poincare polynomials of some of these moduli spaces. We apply these to the moduli spaces of rank 1 and rank 2 torsion free sheaves on weighted projective planes and express the generating function of Euler characteristics in terms of modular forms. We will talk about some applications in the case of moduli spaces on toric 3-folds if time allows.

### Monday, 20 October 2014

#### Topology Seminar

*Maurer-Cartan elements and natural operations*at 2:30p.m. in VinH 570

**Benjamin Ward**(

*Simons Center for Geometry and Physics, Stony Brook University*)

The process of twisting by a Maurer-Cartan element in an operadic context produces cochain complexes computing, for example, the Chevalley-Eilenberg cohomology of a Lie algebra, ...
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#### Automorphic Forms and Number Theory

### Tuesday, 21 October 2014

#### Climate Seminar

*Proposed effects of early agriculture on current climate*at 11:15a.m. in VinH 570

**Elise Reed**(

*U of M Mathematics Department*)

#### Combinatorics Study Group

#### Geometric Analysis Learning Seminar

### Wednesday, 22 October 2014

#### Math Physics Seminar

*Diagnosing Cancer with Signature Curve Symmetry*at 12:20p.m. in VinH 570

**Anna Grim**(

*St. Thomas*)

Mammography persists as a challenge in radiology because the structural differences between benign and malignant tumors are indistinguishable to the human eye. However, the application ...
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#### Student Stochastic Seminar

*Concentration of measure*at 2:00p.m. in VinH 570

**Piotr Nayar**(

*IMA*)

My goal during this talk will be to present some basic theorems and techniques related to concentration of measure phenomenon. We will consider product probability ...
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#### Algebraic Geometry

*Rank 2 Donladson-Thomas theory vertex*at 2:30p.m. in Vincent Hall 313

**Amin Gholampour**(

*(University of Maryland)*)

We study the geometry of moduli space of rank 2 torsion free sheaves on toric 3-folds. As an outcome we develop a vertex theory for ...
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#### Reading Seminar on Automorphic Forms

#### Topology Seminar

*Configurations spaces and symmetric complements*at 3:30p.m. in Vincent Hall 203A

**TriThang Tran**(

*University of Oregon*)

In this talk, we discuss homological stability for spaces that are defined as the complements of the closures of certain strata in the n-fold symmetric ...
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#### Student Symplectic and Low Dimensional Topology Seminar

*Primitive cohomologies on compact symplectic manifolds*at 3:35p.m. in VinH 2

**Heidi Andersen**(

*U of M Mathematics Department*)

Primitive cohomologies on compact symplectic manifolds are defined, and properties (such as finite-dimensionality) explored. These provide new symplectic invariants, as they are distinct from the ...
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### Thursday, 23 October 2014

#### SIAM Student Chapter Reading Group Seminar

*An introduction to frames in finite dimensions*at 11:00a.m. in VinH 570

**Alex Gutierrez**(

*U of M Mathematics Department*)

Christensen's "Frames and Bases: An Introductory Course"

#### Commutative Algebra Seminar

*Matis duality, D-modules, and the Hodge-de Rham spectral sequences for complete local rings III*at 11:15a.m. in VinH 203A

**Nicholas Switala**(

*U of M Mathematics Department*)

#### Math Club Seminar

#### Differential Geometry / Symplectic Topology Seminar

*New Exotic 4-manifolds via Luttinger surgery on Lefschetz fibrations*at 1:25p.m. in VinH 570

**Nur Saglam**(

*U of M Mathematics Department*)

: In this talk, we will present a new construction of symplectic 4-manifolds homeomorphic but not diffeomorphic to (2n+2k-3)CP^2#(6n+2k-3)(-CP)^2 via Luttinger surgery. If time permit, ...
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#### Colloquium

*Geometry of moduli spaces of coherent sheaves on toric surfaces and threefolds*at 3:30p.m. in VinH 16

**Amin Gholampour**(

*University of Maryland*)

We explain how toric methods can be used to explore the geometry of moduli spaces of coherent sheaves. In particular, we review the methods of ...
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### Friday, 24 October 2014

#### Combinatorics Problem Session

*All are welcome to pose a short combinatorics problem, or discuss problems posed by others*at 2:30p.m. in VinH 570

**to be announced**

#### Probability Seminar

*Stochastic block models and planted CSP's*at 2:30p.m. in VinH 207

**Will Perkins**(

*IMA*)

A stochastic block model is a random graph with edge probabilities that differ according to how an edge crosses a planted partition of the vertex ...
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#### Lie Theory Seminar

*Higher Koecher's principle, II*at 3:30p.m. in VinH 209

**Professor Kai-Wen Lan**(

*U of M Mathematics Department*)

This is a continuation of the previous week's talk.

#### Combinatorics Seminar

*Adinkras: Progress and Problems*at 3:35p.m. in VinH 570

**Yan Zhang**(

*UC Berkeley*)

Adinkras are graphical tools created for the study of representations in supersymmetry that turn out to contain many connections with graded posets, the Tutte polynomial, ...
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