Assistant mathematics professor at Baruch College.
 Curriculum Vitae

More about me. Scroll for research.


I use probability to describe complex systems such as epidemics, chemical reactions, and species competition.

2020: Primary investigator for NSF RAPID Grant 2028892: Quarantined Networks and the Spread of COVID-19.

2019 -- 2023: Primary investigator for NSF DMS Grant 2115936: Multitype Particle Systems.

Google Scholar


33. Chase-escape on the configuration model

Electronic Communications in Probability

Emma Bernstein*, Clare Hamblen*, Lily Reeves

32. Safe reopening of university campuses is possible with COVID-19 vaccination

arXiv To appear in PLOS One

Sheng Li, Samitha Samanarake, Matthew Zalesak

31. Diffusion-limited annihilating systems and the icx order

arXiv To appear in Electronic Journal of Probability

Riti Bahl*, Philip Barnet*, Tobias Johnson


30. Three-velocity coalescing ballistic annihilation


Luis Benitez*, Maximus Redman*, Lily Reeves

29. Modeling COVID-19 spread in small colleges


Riti Bahl*, Nicole Eikmeier, Alexandra Fraser*, Felicia Keesing, Kukai Nakahata*, Lily Z. Wang

28. Particle density in diffusion-limited annihilating systems


Tobias Johnson, Hanbaek Lyu, David Sivakoff


27. Parking on supercritical Galton-Watson trees


Riti Bahl*, Philip Barnet*

26. Chase-escape with death on trees

Annals of Probability

Erin Beckman, Keisha Cook, Nicole Eikmeier, Sarai Hernandez-Torres

25. Two-type annihilating systems on the complete and star graph

Stochastic Processes and their Applications

Irina Cristali*, Yufeng Jiang*, Remy Kassem*, David Sivakoff, Grayson York*

24. Critical percolation and A+B-->2A dynamics

Journal of Statistical Physics

23. SIR epidemics on evolving graphs


Yufeng Jiang*, Remy Kassem*, Grayson York*, Rick Durrett

22. The phase structure of asymmetric ballistic annihilation

arXiv To appear in Annals of Applied Probability

Hanbaek Lyu

21. The contact process on periodic trees


Yufeng Jiang*, Remy Kassem*, Grayson York*, Brandon Zhao*, Xiangying Huang, Rick Durrett

20. Cover time for the frog model on trees

Forum of Math, Sigma

Christopher Hoffman, Tobias Johnson

19. The frog model on trees with drift

Electronic Communications in Probability

Erin Beckman, Natalie Frank*, Yufeng Jiang*, Si Tang

18. Coexistence in chase escape

Electronic Communications in Probability

Rick Durrett, Si Tang

17. The upper threshold in ballistic annihilation


Debbie Burdinski*, Shrey Gupta*

16. Poisson percolation on the oriented square lattice

Stochastic Processes and their Applications

Irina Cristali*, Rick Durrett

15. Poisson percolation on the square lattice


Irina Cristali*, Rick Durrett

14. Parking on transitive unimodular graphs

Annals of Applied Probability

Janko Gravner, Hanbaeck Lyu, David Sivakoff

13. Block size in Geometric(p)-biased permutations

Electronic Communications in Probability

Irina Cristali*, Vinit Ranjan*, Jake Steinberg*, Erin Beckman, Rick Durrett, James Nolen

12. Asymptotic shape of the Brownian frog model

Electronic Journal of Probability

Erin Beckman, Emily Dinan, Rick Durrett, Ran Huo

11. Infection spread for the frog model on trees

Electronic Journal of Probability

Christopher Hoffman, Tobias Johnson

10. Coalescing random walk on unimodular graphs

Electronic Communications in Probability

Eric Foxall. Tom Hutchcroft

9. The bullet problem with discrete speeds

Electronic Communications in Probability

Brittany Dygert*, Christoph Kinzel*, Jennifer Zhu*, Annie Raymond, Erik Slivken

8. Ewens sampling and invariable generation

Combinatorics, Probability, and Computing

Gerandy Brito, Christopher Fowler, Avi Levy

7. Stochastic orders and the frog model

Annales de l'Institut Henri Poincaré

Tobias Johnson

6. The critical density for the frog model is the degree of the tree

Electronic Communications in Probability

Tobias Johnson

5. Frog model wakeup time on the complete graph

Rose-Hulman Journal of Undergraduate Research

Nikki Carter*, Brittany Dygert*, Stephen Lacina*, Collin Litterell*, Austin Stromme*

4. Site recurrence for coalescing random walk

Electronic Communications in Probability

Itai Benjamini, Eric Foxall, Ori Gurel-Gurevich, Harry Kesten

3. From transience to recurrence with Poisson tree frogs

Annals of Applied Probability

Christopher Hoffman, Tobias Johnson

2. Choices, intervals and equidistribution

Electronic Journal of Probability

1. Recurrence and transience for the frog model on trees

Annals of Probability

Christopher Hoffman, Tobias Johnson