Dr Theodore Vo

Research Overview

I am interested in the rhythms observed in neural and cardiac systems. I use techniques from pure and applied mathematics to explain the origins and properties of such rhythms. My outputs include using geometric singular perturbation and dynamical systems techniques to explain the bursting oscillations in insulin-secreting pancreatic beta-cells, hormone-secreting pituitary cells, and ventricular cardiac muscle cells which are key to pumping blood through the heart. This work has yielded biological insights and predictions that have been tested by collaborating labs.

My current interests include (i) the development of averaging methods for slow/fast systems in which the fast subsystem manifolds of limit cycles are folded, as often occurs in neuroscience models; (ii)  the analysis of canard-induced pattern formation in reaction-diffusion PDEs with excitable kinetics, such as in cardiac tissue models; and (iii) the analysis of delayed bifurcation phenomena in ODEs and PDEs.

Selected Publications

[1] Kimrey, Joshua ; Vo, Theodore ; Bertram, Richard. "Big Ducks in the Heart: Canard Analysis Can Explain Large Early Afterdepolarizations in Cardiomyocytes". In: SIAM Journal on Applied Dynamical Systems. 2020 ; Vol. 19, No. 3. pp. 1701-1735. https://doi.org/10.1137/19M1300777

[2] Vo, Theodore ; Bertram, Richard ; Kaper, Tasso J. "Multi-mode attractors and spatio-temporal canards". In: Physica D: Nonlinear Phenomena. 2020 ; Vol. 411. https://doi.org/10.1016/j.physd.2020.132544

[3] Vo, Theodore ; Bertram, Richard. "Why pacing frequency affects the production of early afterdepolarizations in cardiomyocytes : An explanation revealed by slow-fast analysis of a minimal model". In: Physical Review E . 2019 ; Vol. 99, No. 5. https://doi.org/10.1103/PhysRevE.99.052205

[4] Kaper, Tasso J. ; Vo, Theodore. "Delayed loss of stability due to the slow passage through Hopf bifurcations in reaction-diffusion equations". In: Chaos. 2018 ; Vol. 28, No. 9. https://doi.org/10.1063/1.5050508

[5] Vo, Theodore ; Kramer, Mark A. ; Kaper, Tasso J. "Amplitude-Modulated Bursting : A Novel Class of Bursting Rhythms". In: Physical Review Letters. 2016 ; Vol. 117, No. 26. https://doi.org/10.1103/PhysRevLett.117.268101