Published on Department of Mathematics Calendar (https://calendar.math.yale.edu)

Week of September 20, 2026

September 21, 2026
Algebraic and Arithmetic Geometry Seminar [3]	Complex structures on S^6	Phil Engel - UIC	4:30pm - KT 801
Arithmetic Algebraic Geometry [4]	Complex structures on S^6	Phillip Engel - UIC	4:30pm - KT 801

September 22, 2026
Geometric Analysis Learning Seminar [5]	Pre-Talk	Yuping Ruan - Yale University	4:00pm - KT 801
Geometric Representation Theory Seminar [6]	Quantum Harish-Chandra bimodules at roots of unity and affine Hecke category	Trung Vu - Yale	4:30pm - KT 329

September 24, 2026
Analysis [7]	Stability of small BGK waves	Wenrui Huang - Brown University	4:00pm - TBA

September 25, 2026
Friday Morning Seminar [8]	Friday morning seminar		10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00pm - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801

Abstracts

Week of September 20, 2026

September 21, 2026
Algebraic and Arithmetic Geometry Seminar [3]	Complex structures on S^6	4:30pm - KT 801	A recent manuscript written by Claude under the direction of Levent Alpoge constructs a 1-parameter family of compact complex threefolds diffeomorphic to S^6. I will describe the main geometric ideas behind the construction and outline the proof. If time permits, I will remark on possible future research directions.
Arithmetic Algebraic Geometry [4]	Complex structures on S^6	4:30pm - KT 801	A recent manuscript written by Claude under the direction of Levent Alpoge constructs a 1-parameter family of compact complex threefolds diffeomorphic to S^6. I will describe the main geometric ideas behind the construction and outline the proof. If time permits, I will remark on possible future research directions.

September 22, 2026
Geometric Analysis Learning Seminar [5]	Pre-Talk	4:00pm - KT 801	This pre-talk will provide background for the Geometric Analysis and Application Seminar on 09/22.
Geometric Representation Theory Seminar [6]	Quantum Harish-Chandra bimodules at roots of unity and affine Hecke category	4:30pm - KT 329	Abstract: Classical Harish-Chandra bimodules are related to many objects in representation theory such as infinite dimensional representations of complex groups viewed as real groups, category O and character sheaves. The notion of Harish-Chandra bimodules for quantum groups was introduced in the works about topological quantum field theory of surfaces. I will mention some results about quantum Harish-Chandra bimodules at odd order roots of unity, connect them to affine Soergel bimodules and coherent sheaves on Steinberg variety.

September 24, 2026
Analysis [7]	Stability of small BGK waves	4:00pm - TBA	Bernstein–Greene–Kruskal (BGK) waves are fundamental inhomogeneous steady states of the one-dimensional Vlasov–Poisson system, introduced in 1957. Despite their classical role, their stability theory remains largely open. The only known result is by Guo-Lin, who considered a special class of small BGK waves. In this talk, I will present a stability–instability criterion for small BGK waves bifurcating from homogeneous equilibria, determined by the behavior of the particle distribution near the separatrix. This is joint work with D. Bian, E. Grenier and B. Pausader.

September 25, 2026
Friday Morning Seminar [8]	Friday morning seminar	10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00pm - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801 , 10:00am to 11:00am - Kline Tower 801

Links
[1] https://calendar.math.yale.edu/list/calendar/grid/week/2026-W38 [2] https://calendar.math.yale.edu/list/calendar/grid/week/2026-W40 [3] https://calendar.math.yale.edu/seminars/algebraic-and-arithmetic-geometry-seminar [4] https://calendar.math.yale.edu/seminars/arithmetic-algebraic-geometry [5] https://calendar.math.yale.edu/seminars/geometric-analysis-learning-seminar [6] https://calendar.math.yale.edu/seminars/geometric-representation-theory-seminar [7] https://calendar.math.yale.edu/seminars/analysis [8] https://calendar.math.yale.edu/seminars/friday-morning-seminar [9] https://calendar.math.yale.edu/list/calendar/grid/week/abstract/2026-W38 [10] https://calendar.math.yale.edu/list/calendar/grid/week/abstract/2026-W40