I  am an associate professor  and director of undergraduate studies in the mathematics department at the University at Buffalo, SUNY.  My office is 211 in the mathematics buildling and my office phone is 716-645-6284 x 137.

Previous to coming to Buffalo I was an associate professor at the University of Toledo mathematics department .

Before that I was an NSF postdoctoral fellow at the University of Georgia math department .  My senior scientist and collaborator was Professor  Dan Nakano .

Snail mail:      
        244 Mathematics Building
        Buffalo, NY  14260-2900.  

Fall2009 Office Hours:  by appt..                   
                        

Email me:  dhemmer@math.buffalo.edu                                

In  2001 I  completed my Ph.D at the University of Chicago math department , working under the supervision of Professor  Jon Alperin .  My research focuses on the modular representation theory of symmetric and general linear groups.

My CV:   Here is my CV as of March 2009.

My Research:
           
            Here is a  research statement  designed for those in my field.

            Here is a research statement designed to be accessible to undergraduate math majors.                                 

Publications:

• "The Ext¹  quiver for completely splittable representations of the symmetric group,"  Journal of Group Theory, (4)   (2001) #4, p. 401-416. pdf    dvi ps
• "Support varieties for modules over symmetric groups," (With Dan Nakano) Journal of Algebra, (254) (2002), p. 422-440. pdf
  
• "Specht filtrations for Hecke algebras of type A," (With Dan Nakano),  J. London Math Society (2) (69) (2004), p. 623-638. pdf
  
• "Fixed-point functors  for symmetric groups and Schur algebras," J. Algebra (280) (2004), p. 295-312.  pdf
• "A row removal theorem for the Ext^1 quiver of symmetric groups and Schur algebras,"  Proc. American Mathematical Society, ( 133)  (2005), p.403-414.   dvi     pdf
• "Representation Type of Schur Superalgebras," (With Kujawa and Nakano), J. Group Theory, (9) (2006) #3, p. 283-306.   pdf   ps
• "Irreducible Specht modules are signed Young modules," J. Algebra (305) (2006) , p.433-441  pdf
• "Cohomology of Specht modules," (with Nakano) J. Algebra (306)  (2006), p. 191-200.   pdf
  
• "Symmetric Group Modules with Specht and Dual Specht Filtrations," Communications in Algebra, 35:11, (2007) 3292 - 3306  pdf
  
• "Cohomology and generic cohomology of Specht modules for the symmetric group," J. Algebra (322) 2009,  1498-1515. pdf
• "The group of endotrivial modules for the symmetric and alternating groups," (With Jon Carlson and Nadia Mazza), to appear , Proc. Edin. Math. Soc. 2009.  pdf
• "The complexity of certain Specht modules for the symmetric group," to appear, Journal of Algebraic Combinatorics, (30) 2009, 421-427.  pdf
• "A combinatorial approach to Specht module cohomology," to appear, Algebra Colloq.  2009.   pdf
• "On the cohomology of Young modules for the symmetric group," (With Fred Cohen and Dan Nakano), submiited 2009.   pdf

• My doctoral disseration (final version! 6/01)  dvi ps

• American Contract Bridge League
• AMS Math on the Web
  
• Groups, Representations and Cohomology Preprint Archive
  
• Drudge Report