Rice University Math Department Calendar

     August 2009           September 2009          October 2009    
 Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
                    1          1  2  3  4  5                1  2  3
  2  3  4  5  6  7  8    6  7  8  9 10 11 12    4  5  6  7  8  9 10
  9 10 11 12 13 14 15   13 14 15 16 17 18 19   11 12 13 14 15 16 17
 16 17 18 19 20 21 22   20 21 22 23 24 25 26   18 19 20 21 22 23 24
 23 24 25 26 27 28 29   27 28 29 30            25 26 27 28 29 30 31
 30 31

3:40 pm Wednesday, September 9, 2009
Stulken Topology Seminar: Graphical methods establishing nontriviality of state cycle Khovanov homology classes
by Andrew Elliott (Rice University) in HB 355

We determine when certain state cycles represent nontrivial Khovanov homology classes by analyzing features of the state graph. Using this method, we are able to produce hyperbolic knots with arbitrarily many diagonals containing nontrivial state cycle homology classes. This gives lower bounds on the Khovanov width of knots whose complexity precludes computation of the full homology.Host Department: Rice University-Mathematics
Submitted by shelly@rice.edu

4:00 pm Wednesday, September 9, 2009
Geometry-Analysis Seminar: Rigidity of Parametric Families of Some Parabolic Algebraic Actions
by Danijela Damjanovic (Rice University) in HB 227

Horocycle flow on the unit tangent bundle of a hyperbolic surface has non-trivial time changes, in fact obstructions to trivialization of a time change are precisely described in the work of Flaminio and Forni. In this talk I will discuss the work of Mieszkowski: trivialization of time changes for a 2-dimensional unipotent algebraic action on the manifold obtained from the product of SL(n, R)s factored by an irreducible lattice. I will then explain how this is used towards understanding perturbations of the action. This is joint work with A. Katok.Host Department: Rice University-Mathematics
Submitted by damanik@rice.edu