## Contact Info

Pure MathematicsUniversity of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x43484

Fax: 519 725 0160

Email: puremath@uwaterloo.ca

Monday, April 5, 2021 — 4:00 PM EDT

**Michael Pinsker, Technische Universität Wien / Charles University Prague**

"Algebraic, logical, and combinatorial methods for Constraint Satisfaction Problems"

Constraint Satisfaction Problems (CSPs) are a kind of computational problem where one is given a finite number of variables along with "constraints" about these variables; the problem is to decide whether or not the variables can be assigned values such that all constraints are satisfied. An example of a CSP is solving equations over a fixed field. The complexity of a CSP depends on the range of the possible values for the variables (e.g., the rational numbers, a finite field,...) and the type of constraints allowed (e.g., any equation, linear equations,...). If this range is finite, then the CSP is either solvable in polynomial time or NP-complete, by a recent theorem of Bulatov and Zhuk which answered a conjecture that had lasted 25 years. I am going to discuss the general algebraic approach used in their proofs, as well as the additional methods from model theory and Ramsey theory required to investigate CSPs if the range is infinite.

Zoom meeting: https://zoom.us/j/93240216981?pwd=aE0vbktRV1NvMTFzbFVaalVpb1pCdz09

University of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x43484

Fax: 519 725 0160

Email: puremath@uwaterloo.ca

University of Waterloo

University of Waterloo

43.471468

-80.544205

200 University Avenue West

Waterloo,
ON,
Canada
N2L 3G1

The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Office of Indigenous Relations.