2025
Statistics Colloquium: Anne van Delft
11:30 am–12:30 pm Jones 303
Anne van Delft, Department of Statistics, Columbia University
Title: A statistical framework for analyzing shape in a time series of random geometric objects (joint work with Andrew J. Blumberg)
Abstract: We introduce a new framework to analyze shape descriptors that capture the geometric features of an ensemble of point clouds. At the core of our approach is the point of view that the data arises as sampled recordings from a metric space-valued stochastic process, possibly ofnonstationary nature, thereby integrating geometric data analysis intothe realm of functional time series analysis. Our framework allows for natural incorporation of spatial-temporal dynamics, heterogeneous sampling, and the study of convergence rates. Further, we derive complete invariants for classes of metric space-valued stochastic processes in the spirit of Gromov, and relate these invariants toso-called ball volume processes. Under mild dependence conditions, a weak invariance principle in $D([0,1]\times [0,\mathscr{R}])$ is established for sequential empirical versions of the latter, assuming the probabilistic structure possibly changes over time. Finally, we use this result to introduce novel test statistics for topological change, which are distribution-free in the limit under the hypothesis of stationarity. We explore these test statistics on time series of single-cell mRNA expression data, using shape descriptors coming from topological data analysis.
Student Seminar: Charlotte Dai
5:30–6:00 pm Jones 111
Thursday, May 8, 2025, at 5:30 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Charlotte Dai, Department of Statistics, The University of Chicago
“Tracing Public Sentiment on Assisted Dying in U.S. Discourse (1930–2010): A Long-Form Text Analysis Using NLP”
Student Seminars: Matthew Kang
5:00–5:30 pm Jones 111
Wednesday, May 7, 2025, at 5:00 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Matthew Kang, Department of Statistics, The University of Chicago
“Forecasting Gamma Squeezes in GameStop Stock”
Billingsley Lectures on Probability: Nina Holden
4:00–5:00 pm Jones 303
We are pleased to have Prof. Nina Holden, Courant Institute of Mathematical Sciences, New York University, as our honored speaker on Thursday, May 8, 2025, at 4:00 PM, Jones 303, 5747 South Ellis Avenue. Proceeding the Lecture, a tea will be held in Jones 304 at 3:30. A reception will immediately follow the lecture at 5:20 pm, in the Stevanovich Center for Financial Mathematics, 5727 South University Avenue.
Title: Scaling limits of random planar maps
Abstract: Planar maps are graphs embedded in the sphere such that no two edges cross, where we view two planar maps as equivalent if we can get one from the other via a continuous deformation of the sphere. In this talk we will present scaling limit results (i.e., convergence results) for random planar maps and we will focus in particular on a notion of convergence known as convergence under conformal embedding.
Student Seminar: Peiran Chen
1:30–2:00 pm Jones 111
Thursday, May 8, 2025, at 1:30 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Peiran Chen Department of Statistics, The University of Chicago
“Comparative Analysis of LLM Alignment Techniques for Open-Source Model”
Student Seminar: Robby Winter
12:00–12:30 pm Jones 111
Thursday, May 8, 2025, at 12:00 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Robby Winter, Department of Statistics, The University of Chicago
“A Multiple Instance Tooth Decay Classifier for Intraoral Images”
Student Seminar: Yunpeng Gao
3:00–3:30 pm Jones 111
Wednesday, May 7, 2025, at 3:00 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Yunpeng Gao, Department of Statistics, The University of Chicago
“Asymptotic Approximations of Forward Differences for the Densities of Sums of i.i.d. Random Variables”
Student Seminars: Jaehong Ahn
2:00–2:30 pm Jones 111
Wednesday, May 7, 2025, at 2:30 PM, in Jones 303, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Jaehong Ahn, Department of Statistics, The University of Chicago
“The Statistical Limit of Arbitrage under Overinference and Underinference”
Student Seminars: An Hui Chang
1:30–2:00 pm Jones 111
Wednesday, May 7, 2025, at 1:30 PM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
An Hui Chang, Department of Statistics, The University of Chicago
“Matrix Completion for Missing Financial Variables: An Empirical Study with Public Firm Data”
Student Seminars: Xinchen Du
11:00–11:30 am Jones 111
Wednesday May 7, 2025, at 11:00 AM, in Jones 111, 5747 S. Ellis Avenue
Master’s Thesis l Presentation
Xinchen Du, Department of Statistics, The University of Chicago
“Online statistical inference for constrained stochastic optimization”