USA Algebra SeminarSpring 2005 |
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Click on the title of a talk for the abstract (if available).
Date |
Speaker |
Topic |
Friday January 21 |
Joerg Feldvoss |
Lie algebras and universal enveloping algebras
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Friday January 28 |
Joerg Feldvoss |
Prime ideals in non-commutative rings |
Friday February 4 |
Joerg Feldvoss |
Injective modules over noetherian rings |
Friday February 11 |
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No seminar |
Friday February 18 |
Joerg Feldvoss |
Injective modules over universal enveloping algebras |
Friday February 25 |
Cornelius Pillen |
Kazhdan-Lusztig polynomials I |
Friday March 4 |
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No seminar |
Friday March 11 |
Mohamed Elhamdadi (University of South Florida) |
Homological algebra of racks and quandles II |
Friday March 18 |
|
No seminar (Spring break) |
Friday March 25 |
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No seminar |
Friday April 1 |
Cornelius Pillen |
Kazhdan-Lusztig polynomials II |
Friday April 8 |
Cornelius Pillen |
Kazhdan-Lusztig polynomials III |
Thursday April 14 |
Brian Boe (University of Georgia) |
Nilpotent matrices in Lie algebras (Colloquium in ILB 360)
It's easy to describe the set of n x n complex matrices whose r-th power is zero: each is conjugate (via an invertible matrix) to a Jordan canonical form matrix with all eigenvalues 0 and blocks of size at most r. In this talk I will discuss work done by the University of Georgia VIGRE Algebra Group on generalizations of this problem. We will consider an arbitrary simple algebraic group G over an algebraically closed field, along with certain embeddings of its Lie algebra g into n x n matrices, and describe the set of elements of g whose r-th power is zero, in terms of G conjugacy classes.
As a corollary, when the characteristic is p, we obtain a description of the ``restricted nullcone'' of g (the case r=p), which is important in the study of Lie algebra cohomology. When p is a ``good prime'' (not too small), this verifies, by much more elementary methods, a 2003 result of Carlson, Lin, Nakano, and Parshall. And when p is ``bad'' (very small), our results are new.
Most of the talk should be accessible to first year graduate students. I will discuss further applications and continuations of our work in my algebra seminar talk.
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Friday April 15 |
Brian Boe (University of Georgia) |
Support varieties for Lie algebras
Support varieties are geometric objects associated to cohomology rings and representations. In the case of modular representations of Lie algebras, it turns out that the supports are subvarieties of the (restricted) nullcone, a very concrete object with a rather well-understood structure. I will discuss recent work of the University of Georgia VIGRE Algebra Group in which we identified explicitly the support varieties of induced modules in the ``bad prime'' setting. This extends the verification by Nakano, Parshall, and Vella of a conjecture of Jantzen for ``good primes.''
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Friday April 22 |
Cornelius Pillen |
Kazhdan-Lusztig polynomials IV |