Becca Thomases

Becca Thomases is an applied mathematician whose research focuses on fluid dynamics, complex fluids, and mathematical modeling. She uses mathematical analysis and computational methods to understand how fluids move and how their behavior changes in the presence of elasticity, complex microstructure, and interactions with moving objects. Her research spans viscoelastic fluid instabilities, swimming microorganisms, and fluid–structure interactions, with recent work exploring elastoviscoplastic flows and reinforcement learning approaches to locomotion.

Before joining Smith College, Thomases was a professor of mathematics at the University of California, Davis, where she served as vice chair for graduate matters and supervised doctoral students.

At Smith, Thomases is committed to making mathematical research accessible to undergraduates. She enjoys developing courses that emphasize active learning, computational experimentation, and mathematical exploration. She created Computational Linear Algebra, a hands-on course using MATLAB, and the Computational and Applied Mathematics Practicum (CAMP), which introduces students to research through an intensive interterm experience. She also works with students on research projects involving mathematical modeling and scientific computing.

Selected Publications

“Corkscrew Motion of Trypanosoma brucei Is Driven by Helical Beating of the Flagellum and Facilitated by Its Bent Shape,” with S. Cheng, D. Das, M. Barchuk, R. Armstrong, M. M. Klingbeil, and S. Zhou. Proceedings of the National Academy of Sciences, 123(27), e2536746123, 2026.

“Emergence of Purely Elastoplastic Turbulence in Shear Flows,” with M. Abdullah, S. Pradeep, D. J. Jerolmack, and P. E. Arratia. Physical Review Letters, 137, 144002, 2026.

“Quantification of Flagellar Gait Changes with Combined Shape Mode Analysis and Swimming Simulations,” with K. E. Gutierrez, P. E. Arratia, and R. D. Guy. Philosophical Transactions of the Royal Society A, 383, 20240505, 2025.

“Effect of Fluid Elasticity on the Emergence of Oscillations in an Active Elastic Filament,” with K. G. Link, R. D. Guy, and P. E. Arratia. Journal of the Royal Society Interface, 21, 20240046, 2024.

“A mathematician’s perspective on the Oldroyd B model: Progress and future challenges”, (with M. Renardy) J. Non-Newtonian Fluid Mech., 293, 104573, 2021.

“Three dimensional viscoelastic instabilities in a four-roll mill geometry at the Stokes limit”, (with P. Gutierrez-Castillo, and A. Kagel) Phys. Fluids, 32, no. 2, 023102, 2020.

“Polymer stress growth in viscoelastic fluids in oscillating extensional flows with applications to micro- organism locomotion”, (with R. D. Guy) J. Non-Newtonian Fluid Mech., 269, pp. 47-56, 2019.

“Convergent solutions of Stokes Oldroyd-B boundary value problems using the Immersed Boundary Smooth Extension (IBSE) method”, (with D.B. Stein, and R.D. Guy) J. Non-Newtonian Fluid Mech., 268, pp. 56-65, 2019.

“Orientation dependent elastic stress concentration at tips of slender objects translating in viscoelastic fluids”, (with C. Li, and R.D. Guy) Phys. Rev. Fluids 4, 031301(R), 2019.

“Proper Orthogonal Decomposition (POD) of the flow dynamics for a viscoelastic fluid in a four-roll mill geometry at the Stokes limit”, (with P. Gutierrez-Castillo) J. Non-Newtonian Fluid Mech., 264, pp. 48-61, 2019.