Steven Byram Roberts
Applied Mathematician
COMP / CASC DIV / Center for Applied Scientific Computing Division
Biography
Steven is an applied mathematician in the Center for Applied Scientific Computing. After completing his Ph.D. in Computer Science and Applications from Virginia Tech in 2021, he joined LLNL as the Sidney Fernbach Postdoctoral Fellow then became a member of the technical staff in 2023. His research interests include
- Ordinary differential equations and differential algebraic equations
- Multirate, implicit-explicit, and splitting methods for multiscale problems
- Sensitivity analysis and adjoint methods
- High-performance computing
- Stiff systems and order reduction
- Machine learning, model order reduction, and surrogate modeling
Steven is a developer for the SUNDIALS suite of time integrators and nonlinear solvers. He is involved in several interdisciplinary research projects through SciDAC partnerships, including
Education
- B.S. Mathematics, Virginia Tech, Blacksburg, VA
- B.S. Computer Science, Virginia Tech, Blacksburg, VA
- Ph.D. Computer Science and Applications, Virginia Tech, Blacksburg, VA
Publications
2026 1 publication
- Roberts, S. B., Aggul, M., Reynolds, D. R., Balos, C. J., Gardner, D. J., & Woodward, C. S. (2026). New Time Integrators and Capabilities in SUNDIALS Versions 6.2. 0-7.4. 0. ACM Transactions on Mathematical Software, 52(1), 1-14. https://doi.org/10.1145/3797888
2023 1 publication
- Balos, C. J., Roberts, S., & Gardner, D. J. (2023). Leveraging Mixed Precision in Exponential Time Integration Methods. In 2023 IEEE High Performance Extreme Computing Conference (HPEC) (pp. 1-8). IEEE. https://doi.org/10.1109/HPEC58863.2023.10363489 (Outstanding Paper Award)
2022 1 publication
- Roberts, S., Popov, A. A., Sarshar, A., & Sandu, A. (2022). A Fast Time-Stepping Strategy for Dynamical Systems Equipped with a Surrogate Model. SIAM Journal on Scientific Computing, 44(3), A1405-A1427. https://doi.org/10.1137/20M1386281
2021 2 publications
- Roberts, S. B. (2021). Multimethods for the Efficient Solution of Multiscale Differential Equations (Doctoral dissertation, Virginia Tech). https://hdl.handle.net/10919/104872
- Roberts, S., Loffeld, J., Sarshar, A., Woodward, C. S., & Sandu, A. (2021). Implicit multirate GARK methods. Journal of Scientific Computing, 87(1), 1-32. https://doi.org/10.1007/s10915-020-01400-z
Awards
Summer 2026: Best Paper Award at European Seminar on Computing
Fall 2023: Outstanding Paper Award at IEEE High Performance Extreme Computing Conference
Fall 2021 – Winter 2023: 2021 Fernbach Postdoctoral Fellow
Fall 2018 – Spring 2020: Virginia Space Grant Consortium Graduate STEM Research Fellowship Recipient
Fall 2017: Recipient of Virginia Tech Davenport Fellowship for research performance and promise
2016: Winner of Virginia Tech David Heilman Memorial Award for Outstanding Undergraduate Research