Mail address: 503 Boston Avenue, Bromfield-Pearson, Room 201, Medford, MA 02155, US.

Email: alexandru (dot) hening (at) tufts (dot) edu

I am an Assistant Professor in the Department of Mathematics at Tufts University. Previously I was 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 1853463.

Here is my CV.

Activities
Research interests
  • 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.
  • 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 and dynamical systems: stationary distributions, quasistationary distributions, ergodic properties.
Publications
  1. Quasi-stationary distributions of multi-dimensional diffusion processes, with Weiwei Qi, Zhongwei Shen and Yingfei Yi, preprint, 2020.
  2. The effects of random and seasonal environmental fluctuations on optimal harvesting and stocking, with Ky Tran and Sergiu Ungureanu, preprint, 2020.
  3. A general theory of coexistence and extinction for stochastic ecological communities, with Peter Chesson and Dang H. Nguyen, submitted, 2020.
  4. Optimal ergodic harvesting under ambiguity, with Asaf Cohen and Chuhao Sun, preprint, 2020.
  5. Stationary distributions of persistent ecological systems, with Yao Li, Journal of Mathematical Biology, under revision, 2020.
  6. A classification of the dynamics of three-dimensional stochastic ecological systems, with Dang H. Nguyen and Sebastian J. Schreiber, submitted, 2020.
  7. Coevolution of patch selection in stochastic environments, with Dang H. Nguyen and Sebastian J. Schreiber, preprint, 2020.
  8. Dynamical systems with fast switching and slow diffusion: hyperbolic equilibria and stable limit cycles, with Dang H. Nguyen, Nguyen H. Du and George Yin, submitted, 2019.
  9. Coexistence, extinction, and optimal harvesting in discrete-time stochastic population models, Journal of Nonlinear Science, to appear, 2020.
  10. Harvesting and seeding of stochastic populations: analysis and numerical approximation, with Ky Tran, Journal of Mathematical Biology, Vol. 81, 65-112, 2020.
  11. 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.
  12. The competitive exclusion principle in stochastic environments, with Dang H. Nguyen, Journal of Mathematical Biology, Vol. 80, 1323-1351, 2020.
  13. Markov processes conditioned on their location at large exponential timeswith Steven N. Evans, Stochastic Processes and their Applications, Vol. 129, Issue 5, 1622-1658, 2019.
  14. Quasistationary distributions for one-dimensional diffusions with two singular boundary pointswith Martin Kolb, Stochastic Processes and their Applications, Vol. 129, Issue 5, 1659-1696, 2019.
  15. Optimal sustainable harvesting of populations in random environmentswith Luis H. R. Alvarez E., Stochastic Processes and their Applications (to appear), 2019.
  16. Harvesting of interacting stochastic populations, with Ky Tran, Tien Phan, and George Yin, Journal of Mathematical Biology, Vol. 79, Issue 2, 533-570, 2019.
  17. Asymptotic harvesting of populations in fluctuating environmentswith Dang H. Nguyen, Sergiu C. Ungureanu and Tak Kwong Wong, Journal of Mathematical Biology, Vol. 78, Issue 1–2, 293–329, 2019.
  18. On a predator-prey system with random switching that never converges to its equilibriumwith Edouard Strickler, SIAM Journal on Mathematical Analysis, Vol. 51, Issue 5, 3625-3640, 2019.
  19. 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.
  20. Coexistence and extinction for stochastic Kolmogorov systemswith Dang H. Nguyen, Annals of Applied Probability, Vol. 28, No. 3, 1893-1942, 2018.
  21. Stochastic Lotka-Volterra food chainswith Dang H. Nguyen, Journal of Mathematical Biology, Vol. 77, Issue 1, 135-163, 2018.
  22. Stochastic population growth in spatially heterogeneous environments: The density-dependent casewith Dang H. Nguyen and George Yin, Journal of Mathematical Biology, Vol. 76, Issue 3, 697–754, 2018.
  23. The free path in a high velocity random flight process associated to a Lorentz gas in an external fieldwith Douglas Rizzolo and Eric S. Wayman, Transactions of the American Mathematical Society, Series B 3 (2016), 27-62.
  24. Transient one-dimensional diffusions conditioned to converge to a different limit point, Statistics and Probability Letters, 110, 62-73, 2016.
  25. When do skew-products exist?with Steven N. Evans and Eric S. Wayman, Electronic Communications in Probability, 20, no. 54, 1-14, 2015.
  26. 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.
  27. Killed Brownian motion with a prescribed lifetime distribution and models of defaultwith Boris Ettinger and Steven N. Evans, Annals of Applied Probability, 24, 1-33, 2014.
  28. Non-existence of Markovian time dynamics for graphical models of correlated defaultwith Steven N. Evans, Queueing Systems, December 2011, Vol. 69, Issue 3-4, 293-312, 2011.
  29. A stochastic Lotka-Volterra system with killingwith Martin Kolb, preprint, 2014.