Professor
Fields of Interest
Biography
PhD, University of California, San Diego, 1994
SB, MIT, 1990
My research is in algebraic combinatorics. Combinatorics is the study of counting and bijective proofs, so an algebraic combinatorialists counts algebraic objects. In particular, I am interested in Schubert polynomials, Schubert varieties, flag manifolds, Kazhdan-Lusztig polynomials, Stanley symmetric functions, Bruhat order, Weyl group and root systems of all types etc. I am a strong advocate of using computers to do math research, in particular for obtaining data for conjectures and computer verified proofs. Recently, I have been interested in problems which are not decidable by any possible algorithm in finite time.
Courses Taught
Spring 2024
Winter 2024
Autumn 2023
Winter 2023
Autumn 2022
Spring 2022
Winter 2022
Autumn 2021
Spring 2021
Winter 2021
Spring 2020
Winter 2020
Autumn 2019
Spring 2019
Winter 2019
Autumn 2018
Winter 2018
Autumn 2017
Spring 2017
Winter 2017
Spring 2016
Winter 2016
Autumn 2015
News & Events
Related News
- Sara Billey is co-recipient of A&S Bergstrom Award - April 26, 2018
- Sara Billey featured in 2013 AWM Grand Prize Winning Essay - April 1, 2013
- AMS Fellows Named - November 1, 2012
Related Events
- Career Transitions: "3-minute Thesis Talks" and "Things I wish I had known: advice from graduating students." (Part 2!) (Full list coming in May) - May 30, 2024 - 3:30pm
- Combinatorics and Geometry Seminar: TBA (Fiona Young, Cornell University) - May 29, 2024 - 3:30pm to 5:00pm
- Career Transitions: "3-minute Thesis Talks" and "Things I wish I had known: advice from graduating students." (Full list coming in May) - May 24, 2024 - 3:30pm
- Combinatorics and Geometry Seminar: TBA (Kevin Liu, University of Washington) - May 22, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: TBA (Hailun Zheng, University of Houston-Downtown) - May 15, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: TBA (Daoji Huang, University of Minnesota) - May 8, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: The inhomogeneous multispecies PushTASEP and Macdonald polynomials (Arvind Ayyer, Indian Institute of Science) - May 1, 2024 - 3:30pm to 5:00pm
- Career Transitions: Industrial Panel 2024 (Ken Chan, Stephen Lewis Bianamara, Harishchandra Ramadas, Jordan Weaver, Ursula Whitcher) - April 25, 2024 - 4:30pm to 6:00pm
- Combinatorics and Geometry Seminar: Smooth Combinatorial Cubes are IDP (Julie Curtis, University of Washington) - April 24, 2024 - 4:10pm to 5:00pm
- Career Transitions: Surviving and Thriving in the First Year of Grad School (Sara Billey, Isabella Novik, Alex Wang (and likely a few more)) - April 18, 2024 - 4:30pm to 6:00pm
- Combinatorics and Geometry Seminar: Shuffle bases and quasisymmetric power sums (Michael Tang, University of Washington) - April 17, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: The Poincare-Extended ab-Index (Galen Dorpalen-Barry, University of Oregon) - April 10, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Increasing subsequences, orbit harmonics, and shadow play (Brendon Rhoades, University of California, San Diego) - April 3, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: The first bijective proof of the ASM theorem (Matjaž Konvalinka, University of Ljubljana) - March 6, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Incidences and Tilings (Sergey Fomin, University of Michigan) - February 28, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Solving puzzles of shellable simplicial spheres (Yirong Yang, University of Washington) - February 21, 2024 - 4:10pm to 5:00pm
- Combinatorics and Geometry Seminar: Moshe's Insanity (Moshe Rosenfeld, University of Washington, Tacoma) - February 14, 2024 - 3:30pm to 5:00pm
- CANCELED: Combinatorics and Geometry Seminar: The Poincare-Extended ab-Index (Galen Dorpalen-Barry, University of Oregon) - February 7, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Tropicalization of the principal minors of positive semidefinite matrices (Cynthia Vinzant, University of Washington) - January 31, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Farahat-Higman Algebras for Classical Linear Groups (Arun Kannan, Massachusetts Institute of Technology) - January 24, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Distributional properties of colored multiset Eulerian polynomials (Danai Deligeorgaki, KTH Royal Institute of Technology) - January 17, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: A regular unimodular triangulation of the matroid base polytope (Gaku Liu, University of Washington) - January 10, 2024 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Numerical semigroups, minimal presentations, and posets (Christopher O'Neill, San Diego State University) - December 6, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: A noncommutative Schur function approach to chromatic symmetric functions (Isaiah Siegl, University of Washington) - November 29, 2023 - 3:30pm to 5:00pm
- Career Transitions: Transition into Research (Stefan Steinerberger (and possibly others)) - November 16, 2023 - 4:30pm to 5:30pm
- Combinatorics and Geometry Seminar: Extremal crystals and atom-positivity (Samuel Armon, University of Southern California) - November 8, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Matroid Schubert varieties and equivariant compactifications (Colin Crowley, University of Oregon) - November 1, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Quantum Bruhat graphs and tilted Richardson varieties (Shiliang Gao, University of Illinois at Urbana-Champaign) - October 25, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Snake Graphs for Graph LP Algebras (Sunita Chepuri, University of Puget Sound) - October 18, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Projections of Richardson Varieties (Travis Grigsby, Oklahoma State University) - October 11, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Face Numbers and Angles of Polytopes (Josh Hinman, University of Washington) - October 4, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Combinatorics of two-boundary Temperley-Lieb algebras (Zajj Daugherty, Reed College) - May 31, 2023 - 3:30pm to 5:00pm
- Career Transitions: Career Transitions: Academic Jobs Panel (Catherine Babecki, Marty Bishop, Kevin Chien, and Xueying Yu) - May 25, 2023 - 4:00pm
- Combinatorics and Geometry Seminar: Combinatorics of CAT(0) cubical complexes, crossing complexes and co-skeletons (Rowan Rowlands, University of Washington) - May 24, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Central transversals and hyperplane arrangements (Pablo Soberón, City University of New York, Baruch College) - May 17, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Tautological classes of matroids (Christopher Eur, Harvard University) - May 10, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Mixed Volumes of Normal Complexes (Lauren Nowak, University of Washington) - May 3, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Chip-firing game on metric graphs and combinatorics of their Jacobians (Farbod Shokrieh, University of Washington) - April 26, 2023 - 3:30pm to 5:00pm
- Career Transitions: Industrial Panel 2023 (Pete Littig, Anusha Sekar, Jair Taylor, and Catherine Williams) - April 20, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: SL_4 web bases from hourglass plabic graphs (Joshua Swanson, University of Southern California) - April 19, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: The Polyhedral Combinatorics of Pivot Rules (Alex Black, University of California Davis) - April 12, 2023 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Higher Weak Order of Affine Permutations (Herman Chau, University of Washington) - March 8, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Algebra, Geometry & Combinatorics of the Pinhole Camera (Rekha Thomas, University of Washington) - March 1, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: The geometric method, matroids and related simplicial complexes (Andrew Berget, Western Washington University) - February 22, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Vertex labeling properties on graphs and complexes (Bruno Benedetti, University of Miami) - February 15, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Combinatorial mutations and birational maps (Ricky Liu, University of Washington) - February 1, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Unimodular triangulations of sufficiently large dilations (Gaku Liu, University of Washington) - January 25, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Transfer systems and model structures for combinatorialists (Kyle Ormsby, University of Washington) - January 18, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Problems around Combinatorial Graphs and Distance Geometry (Stefan Steinerberger, University of Washington) - January 11, 2023 - 4:00pm to 5:30pm
- Combinatorics and Geometry Seminar: Subdivisions of Shellable Complexes (Max Hlavacek, University of California Berkeley) - December 7, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Odd diagrams and patterns (Bridget Tenner, DePaul University) - November 30, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: 3D plabic graphs and cluster structures on type A braid varieties (Melissa Sherman-Bennett, Massachusetts Institute of Technology) - November 16, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: 2-LC triangulated manifolds are exponentially many (Marta Pavelka, University of Miami) - November 9, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: On the anisotropy theorem of Papadakis and Petrotou (Elizabeth Xiao, University of British Columbia) - November 2, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Enumerating interval graphs and d-representable complexes (Amzi Jeffs, Carnegie Mellon University) - October 26, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Hurwitz numbers via topological recursion (Reinier Kramer, University of Alberta) - October 19, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: A Pattern Avoidance Criteria for Smoothness of Positroid Varieties Via Decorated Permutations, Spirographs, and Johnson Graphs (Jordan Weaver, University of Washington) - October 12, 2022 - 4:30pm to 5:30pm
- Combinatorics and Geometry Seminar: Maximal Chain Descent Orders (Stephen Lacina, University of Oregon) - October 5, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Flavors of the Fubini-Bruhat Order (Stark Ryan, University of Washington) - June 1, 2022 - 4:00pm to 5:00pm
- Combinatorics and Geometry Seminar: Higher Categorical Associahedra (Spencer Backman, University of Vermont) - May 25, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Pattern-avoiding parking functions (Lara Pudwell, Valparaiso University) - May 18, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Graph limits and graph homomorphism inequalities (Fan Wei, Princeton University) - May 11, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: A Proof of Grünbaum’s Lower Bound Conjecture for polytopes, lattices, and strongly regular pseudomanifolds (Lei Xue, University of Washington) - May 4, 2022 - 3:30pm to 5:00pm
- Career Transitions: Career Transitions: Industrial Panel 2022 ( Molly Baird, Steve Klee, Zijian Li, and Anusha Sekar ) - April 28, 2022 - 4:30pm to 5:30pm
- Combinatorics and Geometry Seminar: q-Whittaker functions, finite fields, and Jordan forms (Steven Karp, LaCIM, Université du Québec à Montréal) - April 27, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Grothendieck-to-Lascoux Expansions (Tianyi Yu, University of California San Diego) - April 13, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Linear relations among Schubert structure coefficients (Anna Weigandt, Massachusetts Institute of Technology) - April 6, 2022 - 3:30pm to 5:00pm
- Career Transitions: Microsoft Presentation (Elizabeth Wicks, Rukmini Iyer, and Charles Denis) - February 24, 2022 - 4:30pm to 5:30pm
- Combinatorics and Geometry Seminar: Planar Tanglegram Layouts and Edge Insertion (Kevin Liu, University of Washington) - February 16, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Common tangents to polytopes and convex bodies (José Alejandro Samper, Pontificia Universidad Católica de Chile) - February 9, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Non-realizability of polytopes via linear programming (Amy Wiebe, Simon Fraser University) - February 2, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Braiding and twisting open positroid varieties (Christopher Fraser, Michigan State University) - January 19, 2022 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: From symmetric functions, to knots, and back again (Nicolle González, University of California Los Angeles) - December 8, 2021 - 3:30pm to 5:00pm
- CANCELED: Combinatorics and Geometry Seminar: Braiding and twisting open positroid varieties (Christopher Fraser, Michigan State University) - December 1, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Multiplicities of maximal dominant weights of some affine Lie algebra modules (Kailash Misra, North Carolina State University) - November 29, 2021 - 4:10pm to 5:00pm
- Combinatorics and Geometry Seminar: When is the probability of avoiding a graph super-exponentially small? (Rajko Nenadov, Google Zürich) - November 17, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Helly type problems: topology, the cascade conjecture, and graph coloring (Gil Kalai, Hebrew University of Jerusalem, Reichman University, and NYU) - November 10, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Combinatorial atlas for log-concave inequalities (Swee Hong Chan, University of California Los Angeles) - November 3, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: Bumpless pipe dreams encode Gröbner geometry of Schubert polynomials (Patricia Klein, University of Minnesota) - October 27, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: f*- and h*-vectors (Matthias Beck, San Francisco State University) - October 20, 2021 - 3:30pm to 5:00pm
- Combinatorics and Geometry Seminar: P-partition generating functions of naturally labeled posets (Ricky Liu, University of Washington) - October 13, 2021 - 3:30pm to 5:00pm
- Career Transitions: Post-Prelim Chat (Panel Speakers: Silvia Ghinassi, Gaku Liu, and Farbod Shokrieh, Hosted by: Sara Billey) - December 3, 2020 - 12:30pm to 1:30pm
- Career Transitions: Surviving graduate school in the COVID era (Sara Billey and Tatiana Toro, University of Washington) - November 19, 2020 - 4:30pm to 5:45pm
- Career Transitions: Surviving and Thriving in the First Year of Grad School (Sara Billey and Tatiana Toro) - December 5, 2019 - 5:30pm to 6:30pm
- Current Topics Seminar: Session 8 (Sara Billey, Tatiana Toro) - December 5, 2019 - 4:30pm to 5:30pm
- Career Transitions: Career Transitions: Academic Jobs Panel - May 23, 2019 - 4:00pm to 5:00pm
- Career Transitions: Career Transitions: Industry Panel - February 21, 2019 - 4:00pm to 5:00pm
- UW-PIMS Colloquium: Patterns in Standard Young Tableaux (Sara Billey, University of Washington) - November 16, 2018 - 3:30pm to 4:30pm
- Career Transitions: Career Transitions: Industry Panel - February 15, 2018 - 4:00pm to 5:00pm