Calendar
Posted March 27, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:30 pm Lockett 233
Jai Tushar, Louisiana State University
TBD
TBD
Posted January 15, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm – 4:30 pm Lockett Hall 233
Krishnendu Kar, Louisiana State University
TBD
TBD
Posted March 1, 2026
Last modified March 26, 2026
Simon Bortz, University of Alabama
Parabolic Quantitative Rectifiability, Singular Integrals, and PDEs
I will discuss the origins of quantitative rectifiability, starting with the Littlewood–Paley g-function and the Fefferman–Stein characterization of BMO via Poisson extensions. From this point of view, I will describe some of the motivations behind the David–Semmes characterization of uniform rectifiability in terms of Jones’ $L^2$ beta numbers. I will then discuss my work establishing parabolic analogues of some of the equivalences proved by David and Semmes in the elliptic setting, as well as related work by others. I will conclude with recent work connecting this theory to the Dirichlet problem for the heat equation and to quantitative properties of caloric functions.