Thompson Rivers University

Faculty of Science

Faculty of Science

Richard Brewster

Richard Brewster

Richard Brewster

Name: Dr. Richard Brewster
Position: Professor
Affiliation: Mathematics
Phone: 828-5215


Many combinatorial problems lack structure exploitable through existing mathematics. We seek to develop the necessary mathematical theory. By using this interplay of Computer Science and Mathematics, we hope to gain an understanding of the fundamental nature of these challenging combinatorial problems, leading to their practical solutions.

Research Interests

Discrete mathematics; theoretical computer science; computational complexity; graph theory; polynomial time algorithms and good characterizations; graph homomorphisms and colouring problems; domination problems; graph packings and matchings; local search heuristics and discrete optimization.


Ph.D. (Mathematics), Simon Fraser University, 1993 Thesis:"Vertex colourings of edge-coloured graphs"
M.Sc.(Mathematics), University of Victoria, 1988 Thesis:"Irredundant Ramsey numbers"
B.Sc.(Honours, Combined Mathematics and Computer Science), University of Victoria, 1987
Assoc. Dip. of Science, Cariboo College, 1984


Selected Papers in Refereed Journals:

R. C. Brewster R, A. Martens, The reconstruction number of a lexicographic sum of cliques, Journal of Combinatorial Mathematics and Combinatorial Computing, to appear.

R. C. Brewster R, J. Noel J, Mixing Homomorphisms, Recolorings, and Extending Circular Precolorings, Journal of Graph Theory, to appear (published online Dec 2014).

R. C. Brewster, M. H. Nielsen, S. McGuinness, Factors in Graphs with Multiple Degree Constraints, SIAM J. on Discrete Mathematics, 27 (2013), 1734-1747.

R. C. Brewster, C. M. Mynhardt and L. E. Teshima, New bounds for the broadcast domination number of a graph, Central European Journal of Mathematics, 11 (2013),

R. C. Brewster, G. Hahn, S. W. Lamont, C. Lipka, Lexicographic products with high reconstruction numbers, Discrete Mathematics, 312 (2012) 1638-1645.

R. C. Brewster, J. Noel, Extending precolourings of circular cliques, Discrete Mathematics, 312 (2012) 35-41.

R. C. Brewster, D. Funk, Hamilton circles in 6-edge-connected infinite graphs, J of Graph Theory, 71 (2012) 182-191.

R. C. Brewster, G. MacGillivray, and L. Shepherd, The circular chromatic number of hypergraphs, Discrete Mathematics, 309 (2009) 5757-5765 doi:10.1016/j.disc.2008.05.038

R. C. Brewster, T. Graves, Edge switching homomorphisms of edge-coloured graphs, Discrete Mathematics, 309 (2009) 5540-5546. doi:10.1016/j.disc.2008.03.021

R. C. Brewster, T. Feder, P. Hell, J. Huang, G. MacGillivray, Near-unanimity functions and varieties of reflexive graphs, SIAM J. on Discrete Math, 22 (2008) 938-960.

R. C. Brewster, P. Hell, R. Rizzi, Oriented star packings, Journal of Combinatorial Theory, Series B, 98 (2008) 558-576.

R. C. Brewster, T. Graves, On the restricted homomorphism problem, Discrete Applied Mathematics, 156 (2008), 2823-2826 doi:10.1016/j.dam.2007.03.028

R. C. Brewster, G. MacGillivray, Building blocks for the variety of absolute retracts, Discrete Mathematics, 306 (2006) 1758-1764.

Employment History

Professor, TRU, 08/2009
Associate Professor, TRU, 08/2003
Associate Professor, Bishop's University, 07/2002 06/2003
Assistant Professor, Bishop's University, 07/2001 06/2002
Instructor, Regular Full-time, Capilano College, 08/1992 07/2001

Courses Taught

Math 114: Calculus I
Math 117: Calculus for Business
Math 124: Calculus II
Math 138/Comp 138: Discrete Structures
Math 139: Discrete Structures II
Math 170: Discrete Mathematics
Math 222/Comp 220: Discrete Mathematics
Math 270: Discrete Mathematics
Math 312: Intro to Number Theory
Math 317: Calculus IV
Math 340: Linear Programming
Math 351: Problem Solving
Math 441: Discrete Optimization
Math 443: Graph Theory
Math 498: Directed Studies Graph Homomorphisms, Finite Geometries
Math 499 : Selected Topics Polyhedral Matching Theory, Nonlinear programming, Algebraic Graph Theory
Comp 309: Introduction to OS (Bishops)
Math 457: Selected Topics in Math (Bishops)
Comp 305: Theoretical CS (Bishops)
Comp 101: Introduction to CS (Bishops)
Comp 216: Data Communications (Bishops)