Tianyi Yu

Slideshow Image     I am a CRM-ISM postdoc at Université du Québec à Montréal. I got my Ph.D. in 2024 from the University of California, San Diego, where my advisor was Brendon Rhoades. My research is about algebraic combinatorics. Before that, I obtained bachelor's degrees in Mathematics and Computer Science at the University of California, San Diego. My email address is yu.tianyi (at) uqam.ca. My CV is here.

Publications

  1. [PDF] Harmonic bases for generalized coinvariant algebras [with Brendon Rhoades and Zehong Zhao] (Electronic Journal of Combinatorics, 2020.)
  2. [PDF] Grothendieck to Lascoux expansions [with Mark Shimozono] (Transactions of the American Mathematical Society, 2023.)
  3. [PDF] Set-valued tableaux rule for Lascoux polynomials (Combinatorial Theory, 2023.)
  4. [PDF] A bijection between K-Kohnert diagrams and reverse set-valued tableaux [with Jianping Pan] (Accepted, Electronic Journal of Combinatorics, 2023.)
  5. [PDF] A row analogue of Hecke column insertion [with Daoji Huang and Mark Shimozono] (Accepted, Combinatorial Theory.)
  6. [PDF] Top-degree components of Grothendieck and Lascoux polynomials [with Jianping Pan] (Algebraic Combinatorics, 2023.)
  7. [PDF] Connection between Schubert polynomials and top Lascoux polynomials (Submitted)
  8. [PDF] Constructing a Gröbner basis of Griffin's ideal (Submitted)
  9. [PDF] Constructing maximal pipedreams of double Grothendieck polynomials [with Chen-An Chou] (Submitted)
  10. [PDF] Lascoux expansion of the product of a Lascoux and a stable Grothendieck [with Gidon Orelowitz] (Submitted)
  11. [PDF] Grothendieck polynomials of inverse fireworks permutations [with Chen-An Chou] (Submitted)
  12. [PDF] Embedding bumpless pipedreams as Bruhat chains (Submitted)
  13. [PDF] Marked Bumpless Pipedreams and Compatible Pairs [with Daoji Huang and Mark Shimozono]
  14. [PDF] Tableau formula for vexillary double Edelman--Greene coefficients [with Adam Gregory and Zachary Hamaker]
  15. [PDF] Grothendieck positivity for normal square root crystals [with Eric Marberg and Kam Hung Tong]

Conference Proceedings

  1. [PDF] Harmonic bases for generalized coinvariant algebras [with Brendon Rhoades and Zehong Zhao] (FPSAC 2021 conference proceedings.)
  2. [PDF] Grothendieck to Lascoux expansions [with Mark Shimozono] (FPSAC 2022 conference proceedings.)
  3. [PDF] Analogues of two classical pipedream results on bumpless pipedreams (FPSAC 2024 conference proceedings.)

Talks

  1. June, 2021. University of California, San Diego. San Diego, CA (via zoom). [PDF]
  2. September, 2021. University of Minnesota. Minneapolis, MN. [PDF]
  3. September, 2021. University of Illinois, Urbana-Champaign. Urbana, IL. (invited)
  4. September, 2021. University of Waterloo. Waterloo, ON, Canada (via zoom). (invited)
  5. October, 2021. University of California, San Diego. San Diego, CA.
  6. November, 2021. Virginia Polytechnic Institute and State University. Blacksburg, VA.
  7. November, 2021. North Carolina State University. Raleigh, NC. (invited)
  8. January, 2022. FPSAC 2021. Ramat-Gan, Israel (via zoom). [PDF]
  9. February, 2022. University of California, San Diego. San Diego, CA. (advancement) [PDF]
  10. March, 2022. GSCC. University of California, San Diego. San Diego, CA (via zoom). [PDF]
  11. April, 2022. University of Washington. Seattle, WA.
  12. September, 2022. University of Illinois, Urbana-Champaign. Urbana, IL.
  13. September, 2022. University of Minnesota. Minneapolis, MN. (invited)
  14. November, 2022. University of Florida. Gainesville, FL.
  15. November, 2022. University of California, Los Angeles. Los Angeles, CA.
  16. January, 2023. University of California, San Diego. San Diego, CA.[PDF]
  17. March, 2023. GSCC. Washington University in St. Louis. St. Louis, MO.
  18. March, 2023. University of Michigan. Ann Arbor, MI. (invited)
  19. September, 2023. Fields Institute. Toronto, ON, Canada.[PDF]
  20. September, 2023. University of Waterloo. Waterloo, ON, Canada
  21. November, 2023. Virginia Polytechnic Institute and State University. Blacksburg, VA.
  22. November, 2023. University of California, San Diego. San Diego, CA.
  23. November, 2023. Schubert Seminar. Online.[PDF]
  24. December, 2023. Laboratoire d'Algèbre, de Combinatoire et d'Informatique Mathématique. Montréal, QC, Canada.
  25. January, 2024. Combinatorial Algebra meets Algebraic Combinatorics. Montréal, QC, Canada.
  26. January, 2024. University of Southern California. Los Angeles, CA. (invited)
  27. March, 2024. The CAGE (Combinatorics, Algebra, and Geometry) Seminar. Philadelphia, PA.
  28. March, 2024. GSCC. Carnegie Mellon University. Pittsburgh, PA.
  29. April, 2024. Combinatorics And Representation Theory Seminar. Korea Institute For Advanced Study. Korea (via zoom). (invited)
  30. July, 2024. Beijing International Center for Mathematical Research. Beijing, China.
  31. July, 2024. Center for Combinatorics, Nankai University. Tianjin, China.
  32. July, 2024. FPSAC 2024. Bochum, Germany. [PDF][video]
  33. August, 2024. Guangdong Technion-Israel Institute of Technology. Shantou, China.
  34. August, 2024. Sun Yat-sen University. Guangzhou, China.
  35. August, 2024. University of California, San Diego. San Diego, CA(via zoom). (defense)
  36. September, 2024. Hong Kong University of Science and Technology. Hong Kong, China.
  37. November, 2024. Sichuan University. Chengdu, China(via zoom). (invited)
  38. December, 2024. Laboratoire d'Algèbre, de Combinatoire et d'Informatique Mathématique. Montréal, QC, Canada.
  39. January, 2025. University of Florida. Gainesville, FL.
  40. February, 2025. Harvard university. Cambridge, MA.
  41. March, 2025. University of California, San Diego. San Diego, CA.
  42. March, 2025. Texas A & M. College Station, TX.

Courses recently TA'd

  • (WI24) Math 10A Calculus I
  • (FA23) Math 184 Enumerative Combinatorics
  • (SP23) Math 184 Enumerative Combinatorics
  • (WI23) Math 202B Applied Algebra II
  • (WI23) Math 184 Enumerative Combinatorics
  • (FA22) Math 188 Algebraic Combinatorics
  • (FA22) Math 10B Calculus II
  • (SP22) CSE 21 Mathematics for Algorithms and Systems
  • (WI22) Math 10B Calculus II
  • (FA21) CSE 21 Mathematics for Algorithms and Systems
  • (SP21) CSE 21 Mathematics for Algorithms and Systems
  • (WI21) Math 184 Enumerative Combinatorics
  • (FA20) Math 109 Mathematical Reasoning

chi-index

The chi-index measures the walking time from a university's math department to the nearest Chipotle. Here's a ranked list of the chi-indices for the universities where I've given (in-person) seminar talks.
  1. University of Illinois, Urbana-Champaign: 4 min.
  2. North Carolina State University: 6 min.
  3. University of Minnesota: 9 min.
  4. University of Florida: 9 min.
  5. University of Michigan: 10 min.
  6. University of Washington: 11 min.
  7. Virginia Polytechnic Institute and State University: 14 min.
  8. University of California, Los Angeles: 17 min.
  9. Fields Institute: 27 min.
  10. University of California, San Diego: 30 min.
  11. University of Waterloo: 18 hours.