Jonathan Buss

[picture of Prof. Buss]

Good morning! from the Cheriton School of Computer Science in the Faculty of Mathematics of the University of Waterloo. I work in the Algorithms and Complexity Group.

Phone: 1-519-888-4567 x34428
Office: DC 3353
email: jfbuss á

As of June 1, 2023 I am retired from the University of Waterloo. The email address remains valid.


I taught the following courses at various times.

CS 240: Data Structures and Data Management
CS 245: Logic and Computation
CS 251: Computer Organization and Design (formerly Digital Design and Architecture)
CS 341: Algorithms
CS 360: Introduction to Theory of Computation
CS 365: Models of Computation
CS 462/662: Formal Languages and Parsing
CS 464/664: Computational Complexity Theory (no longer offered; see CS 764)
CS 466/666: Algorithm Design and Analysis
CS 764: Computational Complexity
CS 860: Advanced Topics in Algorithms and Complexity


My research work concerned computational complexity and models of feasible computation. In particular, I studied subsets of polynomial-time problems, which better capture the feasibility of computations. Later, I extended the scope to include the W-hierarchy of (possibly) fixed-parameter intractable problems.

Some selected papers

J.F. Buss, T.M. Islam, “The complexity of fixed-parameter problems: guest column”, SIGACT News 39(2008) 33–46.

J.F. Buss, T. Islam, “Algorithms in the W-Hierarchy”, Theory of Computer Systems 41 (2007) 445–457.

J.F. Buss and T. Islam, “Simplifying the Weft Hierarchy,” Theoretical Computer Science 351 (2006) 303–313. (Original version in International Workshop on Parameterized and Exact Computation (IWPEC 2004), Springer, 2004.)

T. Biedl, et al., “Palindrome Recognition Using a Multidimensional Tape,” Theoretical Computer Science, 2003.

N. Immerman, J.F. Buss, and D.A. Mix Barrington, “Number of Variables Is Equivalent To Space,” J. Symbolic Logic 66 (2001) 1217–1230.

J.F. Buss, G.S. Frandsen, and J.O. Shallit, “The Computational Complexity of Some Problems in Linear Algebra,” J. Computer and System Sciences 58 (1999) 572–596.

J.F. Buss and R.B. Simpson, “Planar Mesh Refinement Cannot Be Both Local and Regular,” Numerische Mathematik 79,1 (1998) 1–10.

S.A. Bloch, J.F. Buss and J. Goldsmith, “Sharply-Bounded Alternation and Quasilinear Time”, Theory of Computing Systems 31 (1998) 187-214.

P. Bose, J.F. Buss and A. Lubiw, “Pattern Matching for Permutations”, Information Processing Letters 65,5 (1998) 277-283.

“A Sublinear-Space, Polynomial-Time Algorithm for Directed s-t Connectivity”, 1992, with co-authors Greg Barnes, Larry Ruzzo, and Baruch Schieber.

“Sharply Bounded Alternation within P”, 1995, with co-authors Stephen Bloch and Judy Goldsmith. Archived by the Electronic Colloquium on Computational Complexity.

“Parallel Algorithms with Processor Failures and Delays”, 1991, with co-authors Paris Kanellakis, Prabhakar Ragde, and Alex Shvartsman.

“Lower Bounds on Universal Traversal Sequences Based on Chains of Length Five&rdquo, 1993, with co-author Martin Tompa.

“Processor Networks and Alternation Machines”, Symposium on Parallel Algorithms and Architectures (SPAA), 1990.