Alexandru Hening

I am an Associate Professor in the Department of Mathematics at Texas A&M University.  Previously, I was an Assistant Professor at Texas A&M and Tufts University, a Chapman Fellow at Imperial College London and a postdoctoral researcher at Oxford University. I received my Ph.D. in May 2013 from UC Berkeley. My advisor was Steve Evans.  My research is in part supported by the National Science Foundation under the grant DMS 2147903 and DMS CAREER 2339000. 

email: ahening at tamu dot edu

Here is my CV. 

Activities

• I co-organize the Mathematical Biology Seminar at Texas A&M.

• I am an Associate Editor for Journal of Mathematical Biology and Journal of Biological Dynamics.

• I am a member of the Society of Catholic Scientists.

• I am an advisor at the Thomistic Institute, Texas A&M chapter. 

Research Interests

• population dynamics: stochastic processes in discrete and continuous time, random dynamical systems, ODE, PDE, and their applications to mathematical biology.

• mathematical biology: coexistence theory, population dynamics, spatial ecology, evolutionary processes, nonstationary community theory.

• control problems: optimal control, stochastic control, and their applications to harvesting problems.

• numerical analysis: approximations of invariant probability measures, approximations of stochastic processes.

• long-term behavior of Markov processes: stationary distributions, quasistationary distributions, ergodic properties.

Publications

1. Population dynamics under random switching (with Dang Nguyen, Nhu Nguyen, and Siddharth Sabharwal), preprint, 2024.

2. Longterm behavior of stochastic SIQRS epidemic models, with Dang Nguyen, Trang Ta and Sergiu Ungureanu, submitted, 2024.

3. Stochastic nutrient-plankton models, with Nguyen T. Hieu, Dang Nguyen, and Nhu Nguyen, Journal of Differential Equations, Vol. 376, 370-405, 2023.

4. Population dynamics under demographic and environmental stochasticity, with Weiwei Qi, Zhongwei Shen, and Yingfei Yi, Annals of Applied Probability, to appear, 2024.

5. Quasi-stationary distributions of multi-dimensional diffusion processes, with Weiwei Qi, Zhongwei Shen, and Yingfei Yi, submitted, 2024.

6. Coevolution of patch selection in stochastic environments, with Dang H. Nguyen and Sebastian J. Schreiber, The American Naturalist, Vol. 202, No. 2, 2023.

7. A stochastic epidemic SIR model with hidden states, with Nguyen Du, Nhu Nguyen and George Yin, Nonlinear Analysis: Hybrid Systems, to appear, 2023.

8. A classification of the dynamics of three-dimensional stochastic ecological systems, with Dang H. Nguyen and Sebastian J. Schreiber, Annals of Applied Probability, Vol. 32, No. 2, 893–931, 2022.

9. Random switching in an ecosystem with two prey and one predator, with Dang Nguyen, Nhu Nguyen, and Harrison Watts, SIAM Journal on Mathematical Analysis, Vol. 55, No. 1, 347-366, 2023.

10. Optimal ergodic harvesting under ambiguity, with Asaf Cohen and Chuhao Sun, SIAM Journal on Control and Optimization, Vol. 60, Issue 2, 2022.

11. The effects of random and seasonal environmental fluctuations on optimal harvesting and stocking, with Ky Tran and Sergiu Ungureanu, Journal of Mathematical Biology,  Vol. 84, Article 41, 2022.

12. Optimal sustainable harvesting of populations in random environments, with Luis H. R. Alvarez E., Stochastic Processes and their Applications, Vol. 150, 2022.

13. A general theory of coexistence and extinction for stochastic ecological communities, with Peter Chesson and Dang H. Nguyen, Journal of Mathematical Biology, Vol. 82, Article 56, 2021.

14. Stationary distributions of persistent ecological systems, with Yao Li, Journal of Mathematical Biology, Vol. 82, Article 64, 2021.

15. Dynamical systems under random perturbations with fast switching and slow diffusion: Hyperbolic equilibria and stable limit cycles, with Dang H. Nguyen, Nguyen H. Du, and George Yin, Journal of Differential Equations, Vol. 293, 313-358, 2021.

16. Coexistence, extinction, and optimal harvesting in discrete-time stochastic population models, Journal of Nonlinear Science, Vol. 31, Article 1, 2021.

17. Harvesting and seeding of stochastic populations: analysis and numerical approximation, with Ky Tran, Journal of Mathematical Biology, Vol. 81, 65-112, 2020.

18. The Inverse First Passage Time Problem for killed Brownian motion, with Boris Ettinger and Tak Kwong Wong,  Annals of Applied Probability, Vol. 30, No.3, 1251-1275, 2020.

19. The competitive exclusion principle in stochastic environments, with Dang H. Nguyen, Journal of Mathematical Biology, Vol. 80, 1323-1351, 2020.

20. Markov processes conditioned on their location at large exponential times, with Steven N. Evans, Stochastic Processes and their Applications, Vol. 129, Issue 5, 1622-1658, 2019.

21. Quasistationary distributions for one-dimensional diffusions with two singular boundary points, with Martin Kolb, Stochastic Processes and their Applications, Vol. 129, Issue 5, 1659-1696, 2019.

22. Harvesting of interacting stochastic populations, with Ky Tran, Tien Phan, and George Yin, Journal of Mathematical Biology, Vol. 79, Issue 2, 533-570, 2019.

23. Asymptotic harvesting of populations in fluctuating environments, with Dang H. Nguyen, Sergiu C. Ungureanu, and Tak Kwong Wong, Journal of Mathematical Biology, Vol. 78, Issue 1–2, 293–329, 2019.

24. On a predator-prey system with random switching that never converges to its equilibrium, with Edouard Strickler, SIAM Journal on Mathematical Analysis, Vol. 51, Issue 5, 3625-3640, 2019.

25. Persistence in stochastic Lotka-Volterra food chains with intraspecific competition, with Dang H. Nguyen, Bulletin of Mathematical Biology, Vol. 80, Issue 10, 2527–2560, 2018.

26. Coexistence and extinction for stochastic Kolmogorov systems, with Dang H. Nguyen, Annals of Applied Probability, Vol. 28, No. 3, 1893-1942, 2018.

27. Stochastic Lotka-Volterra food chains, with Dang H. Nguyen, Journal of Mathematical Biology, Vol. 77, Issue 1, 135-163, 2018.

28. Stochastic population growth in spatially heterogeneous environments: The density-dependent case, with Dang H. Nguyen and George Yin, Journal of Mathematical Biology, Vol. 76, Issue 3, 697–754, 2018.

29. The free path in a high velocity random flight process associated to a Lorentz gas in an external field, with Douglas Rizzolo and Eric S. Wayman, Transactions of the American Mathematical Society, Series B 3 (2016), 27-62.

30. Transient one-dimensional diffusions conditioned to converge to a different limit point, Statistics and Probability Letters, 110, 62-73, 2016.

31. When do skew-products exist?, with Steven N. Evans and Eric S. Wayman, Electronic Communications in Probability, 20, no. 54, 1-14, 2015.

32. Protected polymorphisms and evolutionary stability of patch-selection strategies in stochastic environments, with Steven N. Evans and Sebastian J. Schreiber, Journal of Mathematical Biology, 71, Issue 2, 325-359, 2015.

33. Killed Brownian motion with a prescribed lifetime distribution and models of default, with Boris Ettinger and Steven N. Evans, Annals of Applied Probability, 24, 1-33, 2014.

34. Non-existence of Markovian time dynamics for graphical models of correlated default, with Steven N. Evans, Queueing Systems, December 2011, Vol. 69, Issue 3-4, 293-312, 2011.

35. A stochastic Lotka-Volterra system with killing, with Martin Kolb, preprint, 2014.