Jason Schweinsberg
I am a Professor in the Department of Mathematics at
the University of California at San Diego. Before coming to UC San Diego in the
Fall of 2004, I got a Ph.D. in Statistics from the University of California
at Berkeley in 2001, and then spent three years as an NSF postdoc
in the Department of Mathematics at Cornell University.
I work in probability theory, focusing on mathematical problems that arise from the study of evolving populations. Much of my research has been related to
stochastic processes involving coalescence. I have particularly focused on understanding the evolution of populations undergoing selection, often using models based on branching Brownian motion.
I have also done some research on cancer models, looperased random walks, and interacting particle systems.
Address: Department of Mathematics, 0112; University of California,
San Diego; 9500 Gilman Drive; La Jolla, CA 920930112
Email: jschweinsberg@ucsd.edu
Office: 6157 Applied Physics and Mathematics
Teaching
I will be teaching Math 180A in the Winter of 2025 and Math 285 in the Spring of 2025.
Here is a link to a web page where I have compiled some information on graduate programs, REU programs, and careers in Mathematics, which might be of interest to Mathematics majors at UC San Diego.
Here is a link to some information on graduate probability courses, courtesy of Ruth Williams.
Publications

Prediction intervals for neural networks via nonlinear regression
(with Richard De Veaux, Jennifer Schumi, and Lyle Ungar).
Technometrics, 40 (1998), 273282.
Paper

A necessary and sufficient condition for the Λcoalescent to
come down from infinity.
Electron. Comm. Probab., 5 (2000), 111.
Paper

Coalescents with simultaneous multiple collisions.
Electron. J. Probab., 5 (2000), 150.
Paper

Applications of the continuoustime ballot theorem to Brownian motion
and related processes.
Stochastic Process. Appl., 95 (2001), 151176.
Paper

An O(n^{2}) bound for the relaxation time of a Markov chain on cladograms.
Random Struct. Alg., 20 (2002), 5970.
Paper

Conditions for recurrence and transience of a Markov chain on
Z+ and estimation of a geometric success probability
(with James P. Hobert).
Ann. Statist. 30 (2002), 12141223.
Paper

Coalescent processes obtained from supercritical GaltonWatson processes.
Stochastic Process. Appl., 106 (2003), 107139.
Paper

Selfsimilar fragmentations and stable subordinators (with Grégory Miermont).
Séminaire de Probabilités, XXXVII, Lecture Notes in Math., 1832, pp. 333359, Springer, Berlin (2003).
Paper

Stability of the tail Markov chain and the evaluation of improper priors
for an exponential rate parameter (with James P. Hobert and Dobrin Marchev).
Bernoulli, 10 (2004), 549564.
Paper

Approximating selective sweeps (with Richard Durrett).
Theor. Popul. Biol. 66 (2004), 129138.
Paper

Alphastable branching and betacoalescents (with Matthias Birkner,
Jochen Blath, Marcella Capaldo, Alison Etheridge, Martin Möhle, and
Anton Wakolbinger).
Electron. J. Probab. 10 (2005), 303325.
Paper

Improving on bold play when the gambler is restricted.
J. Appl. Probab. 42 (2005), 321333.
Paper

Random partitions approximating the coalescence of lineages during
a selective sweep (with Rick Durrett).
Ann. Appl. Probab. 15 (2005), 15911651.
Paper

A coalescent model for the effect of advantageous mutations on the
genealogy of a population (with Rick Durrett).
Stochastic Process. Appl. 115 (2005), 16281657.
Paper

Power laws for family sizes in a duplication model (with Rick Durrett).
Ann. Probab. 33 (2005), 20942126.
Paper

Betacoalescents and continuous stable random trees (with Julien Berestycki and Nathanaël Berestycki). Ann. Probab. 35 (2007), 18351887.
Paper

Small time behavior of beta coalescents (with Julien Berestycki and Nathanaël Berestycki). Ann. Inst. H. Poincaré Probab. Statist. 44 (2008), 214238.
Paper

Spatial and nonspatial stochastic models for immune response (with Rinaldo B. Schinazi). Markov Process. Related Fields 14 (2008), 255276.

A contact process with mutations on a tree (with Thomas M. Liggett
and Rinaldo B. Schinazi). Stochastic Process. Appl. 118 (2008), 319332.
Paper

Looperased random walk on finite graphs and the Rayleigh process. J. Theoret. Probab. 21 (2008), 378396.
Paper

Waiting for m mutations. Electron. J. Probab. 13 (2008), 14421478.
Paper

The looperased random walk and the uniform spanning tree on the fourdimensional discrete torus. Probab. Theory Related Fields.
144 (2009), 319370. Paper

A waiting time problem arising from the study of multistage carcinogenesis (with Rick Durrett and Deena Schmidt).
Ann. Appl. Probab. 19 (2009), 676718. Paper

The number of small blocks in exchangeable random partitions. ALEA Lat. Am. J. Probab. Math. Stat. 7 (2010), 217242.
Paper

Survival of nearcritical branching Brownian motion (with Julien Berestycki and Nathanaël Berestycki). J. Statist. Phys. 143 (2011), 833854.
Paper

Consensus in the twostate Axelrod model (with Nicolas Lanchier). Stochastic Process. Appl. 122 (2012), 37013717.
Paper

Dynamics of the evolving BolthausenSznitman coalescent. Electron. J. Probab. 17 (2012), no. 91, 150.
Paper

The genealogy of branching Brownian motion with absorption (with Julien Berestycki and Nathanaël Berestycki). Ann. Probab. 41 (2013), 527618.
Paper

The evolving beta coalescent (with Götz Kersting and Anton Wakolbinger). Electron. J. Probab. 19 (2014), no. 64, 127.
Paper

Critical branching Brownian motion with absorption: survival probability (with Julien Berestycki and Nathanaël Berestycki). Probab. Theory Related Fields 160 (2014), 489520.
Paper

Critical branching Brownian motion with absorption: particle configurations (with Julien Berestycki and Nathanaël Berestycki).
Ann. Inst. H. Poincaré Probab. Statist. 51 (2015), 12151250.
Paper

Rigorous results for a population model with selection I: evolution of the fitness distribution. Electron. J. Probab. 22 (2017), no. 37, 194.
Paper

Rigorous results for a population model with selection II: genealogy of the population. Electron. J. Probab. 22 (2017), no. 38, 154.
Paper

A phase transition in excursions from infinity of the "fast" fragmentationcoalescence process (with Andreas Kyprianou, Steven Pagett, and Tim Rogers).
Ann. Probab. 45 (2017), 38293849.
Paper

The size of the last merger and time reversal in Λcoalescents (with Götz Kersting and Anton Wakolbinger).
Ann. Inst. H. Poincaré Probab. Statist. 54 (2018), 15271555.
Paper

The nested Kingman coalescent: speed of coming down from infinity (with Airam Blancas, Tim Rogers, and Arno SiriJégousse).
Ann. Appl. Probab. 29 (2019), 18081836.
Paper

Mutation timing in a spatial model of evolution (with Jasmine Foo and Kevin Leder).
Stochastic Process. Appl. 130 (2020), 63886413.
Paper

A Gaussian particle distribution for branching Brownian motion with an inhomogeneous branching rate (with Matthew Roberts).
Electron. J. Probab. 26 (2021), 176.
Paper

Λcoalescents arising in a population with dormancy (with Fernando Cordero, Adrián González Casanova, and Maite WilkeBerenguer).
Electron. J. Probab. 27 (2022), 134.
Paper

Yaglomtype limit theorems for branching Brownian motion with absorption (with Pascal Maillard). Annales Henri Lebesgue 5 (2022), 921985.
Paper

Particle configurations for branching Brownian motion with an inhomogeneous branching rate (with Jiaqi Liu). ALEA Lat. Am. J. Probab. Math. Stat. 20 (2023), 731803.
Paper

cloneRate: fast estimation of singlecell clonal dynamics using coalescent theory (with Brian Johnson, Yubo Shuai, and Kit Curtius). Bioinformatics 39 (2023), btad561.
Paper

A spatial mutation model with increasing mutation rates (with Brian Chao). J. Appl. Probab. 60 (2023), 11571180.
Paper
Preprints

Asymptotics for the site frequency spectrum associated with the genealogy of a birth and death process (with Yubo Shuai). Paper

The alltime maximum for branching Brownian motion with absorption conditioned on longtime survival (with Pascal Maillard).
Paper

Phase transition of the consistent maximal displacement of branching Brownian motion (with Julien Berestycki, Jiaqi Liu, and Bastien Mallein).
Paper

The Accumulation of Beneficial Mutations and Convergence to a Poisson Process (with Nantawat Udomchatpitak).
Paper
Slides for Talks

"A coalescent model for the effect of advantageous mutations on the genealogy of a population", Paris, September 2007.
Slides

"The looperased random walk and the uniform spanning tree on the fourdimensional discrete torus", San Diego, January 2008.
Slides

"A waiting time problem arising from the study of multistage carcinogenesis", Beijing, June 2009.
Slides

"The genealogy of branching Brownian motion with absorption", Paris, December 2009.
Slides

"Modeling the genealogy of populations using coalescents with multiple mergers", Singapore, March 2011.
Slides

"Dynamics of the evolving BolthausenSznitman coalescent", Mathematical Biosciences Institute, September 2011.
Slides
Video

"Mathematical population genetics and coalescent theory" (series of four 90minute lectures), Indian Institute of Science, Bangalore, January 2013.
Slides

"Rigorous results for a population model with selection", Isaac Newton Institute, Cambridge, March 2015.
Slides
Video

"The nested Kingman coalescent: speed of coming down from infinity", IMS Annual Meeting, Vilnius, Lithuania, July 2018.
Slides

"Yaglomtype limit theorems for branching Brownian motion with absorption", Isaac Newton Institute, Cambridge, July 2018.
Slides
Video

"A Gaussian particle distribution for branching Brownian motion with an inhomogeneous branching rate", One World Probability Seminar, May 2020.
Slides
Video

"Modeling the evolution of populations undergoing selection using branching Brownian motion" (series of five 60minute lectures), Centre de Recherches Mathématiques, Montreal, May 2022.
Slides
Video 1
Video 2
Video 3
Video 4
Video 5

"Λcoalescents arising in a population with dormancy", Hausdorff Institute, Bonn, June 2022.
Slides
Video

"Asymptotics for the site frequency spectrum associated with the genealogy of a birth and death process", Toulouse, May 2023.
Slides

"Speciation induced by dormancy in a model with changing environment", CIRM, Luminy, May 2024.
Slides
Video