Research Interests
My doctoral dissertation research was on the fundamental matrix of constrained minimization and dealt with generalized inverses of matrices. After that I did further work on generalized inverses, and also research on integer matrices and con-similarity of matrices. My recent research is in the area of combinatorial matrix theory, with an emphasis on sign pattern and ray pattern matrices. Recent research also includes graph theory, eigenvalue interlacing, and tournament matrices, generalized complementary basic matrices, and Gersgorin theory. I am a member of the American Mathematical Society and the International Linear Algebra Society . Please link to my brief vita.A Few of My Mathematical Ancestors
George Frobenius
Issai Schur
Alfred Brauer
Richard Painter
Carl D. Meyer (dissertation advisor)
Other ancestors include David Hilbert, Joseph Lagrange, and Carl Gauss.
Personal Information
I was born and grew up in San Antonio, Texas. On my mother's side, my grandfather at a young age came from a
small village in Moravia (which is now part of the Czech Republic) to Cameron in central Texas. These grandparents had fifteen children (some
died young) plus an adopted child, and the family worked hard in farming cattle, cotton, and other crops. As a
result of the conditions, my mother was able to receive only a sixth grade education. My father originally
came from Louisiana to Texas. His parents died when he was young and he was raised by an aunt. He always had
to work while he was in school, but he did have one year in college. I have two sisters and a brother.
Formerly, I served in Nigeria as a member of the United States Peace Corps. Prior to coming to Georgia State
University, I was a faculty member at Pembroke State Universty. Pembroke, NC is the center of the Lumbee Indian
community. I have been at Georgia State University since 1978. My wife, Anne, and I have two children, Genevieve
and Timothy. I enjoy tennis, hiking, traveling, and volunteer work.