Andrew Sack

I'm Andrew, a fifth year math graduate student. My preferred pronouns are he/him. My advisor is Pavel Galashin.

Next academic year I will be a Parekh family fellow at the University of Michigan. You can find my CV here.

I am currently supported by the NSF GRFP Fellowship.

Contact Information:

Office: MS 5351


My research focuses primarily on polyhedral combinatorics and in particular, the combinatorics of poset associahedra.


  1. Operahedron Lattices (with C. Defant) | arXiv:2402.12717
  2. Poset Associahedra and Stack-sorting (with S. Ngyuen) | arXiv:2310.02512
  3. The poset associahedron f-vector is a comparability invariant (with S. Ngyuen) | arXiv:2310.00157
  4. A realization of poset associahedra | arXiv:2301.11449
  5. On audio enhancement via online non-negative matrix factorization. (with W. Jiang, M. Perlmutter, P. Salanevich, and D. Needell) CISS 2022 | arXiv:2110.03114

Teaching (click for links):

Fall 2021

115A Linear Algebra

131A Analysis

Winter 2021

Math 115AH Linear Algebra

Fall 2020

Math 115A Linear Algebra

Fall 2019

Math 61 Discrete Structures


I offer private tutoring in UCLA classes Math 3A, 3B, 3C, 31A, 31B, 33A, 61, 115A and 115B, among others. I also offer tutoring in high school classes such as AP Calculus or IB Math. If you are interested, send me an email.

Note: I will not privately tutor any student in a class for which I currently grade.


I run a youtube channel about math! Check it out!

I have also made some videos on TikTok about math. Check them out here.