I am a Miller postdoctoral fellow in the mathematics department at UC Berkeley. My research is focused on designing computational techniques for solving large-scale computational problems in machine learning, quantum information, and scientific computing, with a focus on randomized algorithms. I received my PhD in Applied and Computational Mathematics from Caltech.
I have been recognized for my work with finalist status for the Hertz foundation fellowship, Caltech’s Thomas A. Tisch Prize for Graduate Teaching in CMS and W. P. Carey & Co. Prize in Applied Mathematics, and the SIAM Student Paper Prize. I grateful to have had my PhD research supported by a Department of Energy Computational Science Graduate Fellowship.
Recent publications:
- T. Chen, E. N. Epperly, R. A. Meyer, C. Musco, & A. Rao (2025) Does block size matter in randomized block Krylov low-rank approximation? arXiv preprint arXiv:2508.06486.
- E. N. Epperly, J. A. Tropp, & R. J. Webber (2025). Embrace rejection: Kernel matrix approximation by accelerated randomly pivoted Cholesky. SIAM Journal on Matrix Analysis and Applications, accepted. (preprint)
- E. N. Epperly, A. Greenbaum, & Y. Nakatsukasa (2025). Stable algorithms for general linear systems by preconditioning the normal equations. arXiv preprint arXiv:2502.17767.
Some of my favorite projects:
- Y. Chen, E. N. Epperly, J. A. Tropp, & R. J. Webber (2025). Randomly pivoted Cholesky: Practical approximation of a kernel matrix with few entry evaluations. Communications on Pure and Applied Mathematics. (preprint)
- E. N. Epperly, M. Meier, & Y. Nakatsukasa (2025). Fast randomized least-squares solvers can be just as accurate and stable as classical direct solvers. Communications on Pure and Applied Mathematics, accepted. (preprint)
- E. N. Epperly, J. A. Tropp, & R. J. Webber (2024). XTrace: Making the most of every sample in stochastic trace estimation. SIAM Journal on Matrix Analysis and Applications. (preprint)
- E. N. Epperly, L. Lin, & Y. Nakatsukasa (2022). A theory of quantum subspace diagonalization. SIAM Journal of Matrix Analysis and Applications. (preprint)