**SMS scnews item created by John Enyang at Sun 17 Mar 2013 1933**

Type: Seminar

Modified: Sun 17 Mar 2013 1938; Mon 18 Mar 2013 1623; Mon 18 Mar 2013 1630

Distribution: World

Expiry: 23 Mar 2013

**Calendar1: 22 Mar 2013 1430-1520**

**CalLoc1: Carslaw 273**

Auth: enyang@penyang.pc (assumed)

### Algebra Seminar

# Characteristic varieties and resonance varieties

### Dimca

###### Friday 22nd March, 2:30-3:20pm, Carslaw 273 (please note the updated venue)

###### Speaker:

Alex Dimca (Université de Nice - Sophia Antipolis)

###### Title:

Characteristic varieties and resonance varieties

###### Abstract:

The characteristic varieties encode the dimensions of the twisted cohomology groups of a space \( X\).
The resonance varieties encode the dimensions of the cohomology groups of Aomoto complexes \(A^*_a=(H^*(X), a \cup)\) built with the cohomology algebra \(H^*(X)\). In many cases (e.g. \(X\) is a projective complex manifold or \(X\) a hyperplane arrangement complement), the relation between the two types of varieties is rather simple.
In this talk I discuss the general case when \(X\) is a smooth quasi-projective manifold.

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We will take the speaker to lunch before the talk.

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

John Enyang John.Enyang@sydney.edu.au