# Richard Hammack

Professor Department of Mathematics and Applied Mathematics

rhammack@vcu.edu

(804) 828-6237

**EDUCATION**

Ph.D. in Mathematics, University of North Carolina at Chapel Hill, 1996

MS in Computer Science, Virginia Commonwealth University, 1988

B.F.A. in Painting, Rhode Island School of Design, 1983

**RESEARCH**

Graph theory and combinatorics, especially product graphs and cycle structures; also the interconnections between mathematics and the visual arts

**SELECTED PUBLICATIONS**

Handbook of product graphs, Second edition, by R. Hammack, W. Imrich, and S. Klavžar, *CRC Press, Boca Raton, FL,* 2011.

A prime factor theorem for bipartite graphs, *European Journal of Combinatorics, *in press*.*

Zero divisors among digraphs (with Heather Smith), *Graphs and Combinatorics*, **30**(1), 171–181, 2014.

Cancellation of digraphs over the direct product, *European Journal of Combinatorics, ***34:** 846–858, 2013.

On uniqueness of prime bipartite factors of graphs,* Discrete Mathematics*, **313**: 1018–1027, 2013.

Cancellation of direct products of digraphs (with Katherine Toman), *Discussiones Mathematicae Graph Theory, ***30**(4): 575–590, 2010.

Direct product factorization of bipartite graphs with bipartition-reversing involutions (with Ghidewon Abay-Asmerom, Craig Larson and Dewey Taylor), *SIAM Journal on Discrete Mathematics*, **23**(4): 2042–2052, 2010.

On Cartesian skeletons of graphs (with Wilfried Imrich), *Ars Mathematica Contemporanea*, **2**(2): 191–205, 2009.

Proof of a conjecture concerning the direct product of bipartite graphs, European Journal of Combinatorics (Special Issue on **44**: 265–272, 2009.

On direct product cancellation of graphs, *Discrete Mathematics*, **309**: 2538–2543, 2009.

**PROFESSIONAL MEMBERSHIPS**

American Mathematical Society

Mathematical Association of America