Tamarkin Assistant Professor
sachi_hashimoto at brown dot edu
Office: Kassar 310
I am broadly interested in number theory and algebraic geometry. More specifically, I am interested in rational points and explicit methods in arithmetic geometry.
- Towards a Classification of Isolated j-invariants (with Abbey Bourdon, Timo Keller, Zev Klagsbrun, David Lowry-Duda, Travis Morrison, Filip Najman, and Himanshu Shukla, and an appendix by Maarten Derickx and Mark van Hoeij), arXiv:2311.07740.
- Self-dual matroids from canonical curves (with Alheydis Geiger, Bernd Sturmfels, and Raluca Vlad), to appear in Experimental Mathematics.
- Geometric quadratic Chabauty and p-adic heights (with Juanita Duque-Rosero and Pim Spelier), Expositiones Mathematicae, 41, (2023), no. 3, 631–674.
- Quadratic Chabauty and p-adic Gross-Zagier, Transactions of the American Mathematical Society, 376, (2023), no. 5, 3725-3760.
- A geometric linear Chabauty comparison theorem (with Pim Spelier), Acta Arithmetica 202 (2022), no. 1, 67–88. 11G30 (11D45).
- A transcendental Brauer-Manin obstruction to weak approximation on a Calabi-Yau threefold (with Katrina Honigs, Alicia Lamarche, and Isabel Vogt, and an appendix by Nicolas Addington),
Research in Number Theory 8 (2022), no. 1, Paper No. 12.
38406501359372282063949 & all that: Monodromy of Fano Problems (with Borys Kadets), International Mathematics Research Notices (2020), rnaa275.
- Chabauty-Coleman computations on rank 1 Picard curves (with Travis Morrison), Arithmetic Geometry, Number Theory, and Computation, Simons Symposia, Springer, 2021, 485-506.
- Computing rational points on rank 0 genus 3 hyperelliptic curves (with María Inés de Frutos-Fernández), Arithmetic Geometry, Number Theory, and Computation, Simons Symposia, Springer, 2021, 449-460.
Here are some expository notes on the geometric quadratic Chabauty theory of Edixhoven and Lido.
I'm co-organizing the algebra seminar at Brown University this year -- let me know your suggestions!
I organized "Number Theory meets Tropical Geometry: the semistable reduction of curves" at MPI Leipzig in April 17 - 21.
Teaching and Outreach
- Math 0520, Section 04, Linear Algebra, T/Th 1:00-2:20 (Fall 2023)
- Math 0520, Section 05, Linear ALgebra, T/Th 10:30-11:50 (Fall 2023)
- Directed Reading Program at Boston University, co-founder and co-director, 2018 - 2022
- Proof School, 2015-2017, middle and high school teacher
- Canada/USA Mathcamp, summers 2014, 2015, 2016, 2019
- Love Math!, a festival for girls, co-founder and co-director, 2016 - 2019.