Scientific interests
My main research area is generalized inverses, studied through an algebraic lens. This includes generalized inverses of matrices over rings, partial orderings, and generalized inverses on rings and semigroups.
I completed my PhD under the supervision of Roland Puystjens (Universiteit Gent, Belgium), and have had longstanding collaborations with Robert E. Hartwig (NCSU, USA) and Nieves Castro-Gonzalez (Universidad Politécnica de Madrid). More recently, colleagues from my own department have joined this line of research.
Other mathematical interests include algebraic coding theory (block and convolutional codes) and cryptography.
Courses & notes
Some courses I've taught (and genuinely enjoyed) led to course notes — feel free to use them.
Recent editions: Coding Theory 2005/06 · Discrete Mathematics 2005/06 · Linear Algebra 2008/09 · Number Theory 2008/09
Research output
A full list of publications, including journal articles and conference proceedings, is available via Scopus.
📄Research collaboration
I've had the pleasure of working with colleagues from around the world:
Erdős number & service
My Erdős number is 4. Here's the chain:
I serve as referee for several scientific journals, including ELA — Electronic Linear Algebra, Linear and Multilinear Algebra, Journal of Algebra and its Applications, Applied Mathematics Letters, Linear Algebra and its Applications, and others. I'm also a reviewer for MathSciNet.
Other interests
Outside of mathematics, I'm interested in hi-fi audio — though I wouldn't call myself an audiophile. My setup revolves around a Denon 2900 as the digital source (SACD + DVD-Audio) and a Denon 3803 receiver, with Visonik Evolution speakers for front, surround, and centre channels.
I've also been a Linux user since 2000, having gone through Mandrake, SuSE, MEPIS, and Kororaa (Gentoo-based, with XGL). Labs here run Fedora Core; our server uses CentOS. Favourite tools: Firefox, Kile + LaTeX, Octave/PARI-GP, Emacs, GIMP, and — yes — vi.