Organizers

prof. dr hab. Rafał Latała

Information

Thursdays, 12:15 p.m. , room: 3160

Home page

http://lists.mimuw.edu.pl/listinfo/sem-rp

List of talks

Feb. 27, 2025, 12:15 p.m.
Marta Strzelecka (University of Warsaw)
Operator \ell_p to \ell_q norms of structured Gaussian matrices (Operator \ell_p to \ell_q norms of structured Gaussian matrices)
We report the progress in two-sided bounds for operator norms from \ell_p to \ell_q of structured Gaussian matrices in the case when p^*,q>=2. Guédon, Hinrichs, Litvak and Prochno conjectured that in this range an easy …
Jan. 16, 2025, 12:15 p.m.
Adam Osękowski (Uniwersytet Warszawski)
Two-weight inequalities for certain dyadic operators (Nierówności dwuwagowe dla pewnych diadycznych operatorów)
We will be interested in a certain special class of martingale operators, which can be regarded as discrete analogues of classical operators of harmonic analysis: singular integrals and Riesz potentials. We will provide the characterization …
Dec. 19, 2024, 12:15 p.m.
Daniel Murawski (Uniwersytet Warszawski)
Optimal constants C_{p, 4} in Khintchine inequality (Optimal constants C_{p, 4} in Khintchine inequality)
We prove that whenever S is a weighted sum of n independent Rademacher random variables, then ||S||_p / ||S||_4 \leq ||G||_p / ||G||_4, where G is a standard Gaussian random variable and p \geq 4. …
Dec. 12, 2024, 12:15 p.m.
Michał Strzelecki (Uniwersytet Warszawski)
Lower bounds for weak-type constants of some operators (Lower bounds for weak-type constants of some operators)
In the talk I shall present a counterexample to a conjecture of Gill about the exact value of the weak-type (1,1) constant of some Hardy-type operators (which arise when one restricts the Beurling-Ahlfors transform to …
Nov. 28, 2024, 12:15 p.m.
Maciej Rzeszut
Gaussian approximation of B-splines in Schwartz seminorms (Gaussian approximation of B-splines in Schwartz seminorms)
We consider sections of the $n-1$ dimensional simplex $\Delta_{n-1}= \left\{y\in\R_+^n: \sum_k y_k= 1\right\}$ by hyperplanes $\sum x_k y_k=t$, for a vector $x$ satisfying the assumptions of Berry-Esseen theorem, i.e. $\sum x_k=0,\sum x_k^2=1$ and $m^3:=\sum\left|x_k\right|^3$ is …
Nov. 21, 2024, 12:15 p.m.
Dominik Kutek (University of Warsaw)
Bregman variation of semimartingales (Bregman variation of semimartingales)
The quadratic variation is a key concept in stochastic calculus, with widespread applications in mathematics and economy. The talk will be about a similar, but more general concept, the Bregman variation (or phi-variation) of semimartingales. …
Nov. 14, 2024, 12:15 p.m.
Peter Pivovarov (Univeristy of Missouri)
Stochastic methods in dual Brunn--Minkowski theory (Stochastic methods in dual Brunn--Minkowski theory)
The surface area of a convex body can be obtained as an average of the areas of its shadows (1-codimensional projections). In turn, the surface area is just one of the k-quermassintegrals of a convex …
Nov. 7, 2024, 12:15 p.m.
Tomasz Tkocz
Convexity properties of sections and Rademacher sums (Convexity properties of sections and Rademacher sums)
I shall discuss certain convexity properties of hyperplane sections of 1-symmetric convex bodies as well as Rademacher sums, which are motivated by chessboard cutting problems and the logarithmic Brunn-Minkowski problem.
Oct. 31, 2024, 12:15 p.m.
Witold Bednorz (Uniwersytet Warszawski)
Some consequences of the new approach to positive stochastic processes. (Some consequences of the new approach to positive stochastic processes.)
In my talk I will explain our idea of an equivalent characterization of the supremum expectation of positive stochastic processes. Some consequences will be discussed, in particular for the Sudakov minoration for canonical processes based …
Oct. 17, 2024, 12:15 p.m.
Rafał Latała (Uniwersytet Warszawski)
Operator \ell_p to \ell_q norms of structured Gaussian matrices (Operator \ell_p to \ell_q norms of structured Gaussian matrices)
We discuss two-sided bounds for operator \ell_p to \ell_q norms of structured Gaussian matrices in the case 1\le p\le 2\le q\leq \infty. Guédon, Hinrichs, Litvak and Prochno conjectured that an easy lower bound for the …
Oct. 10, 2024, 12:15 p.m.
Adam Osękowski (Uniwersyte Warszawski)
Fefferman's inequality for analytic functions (Nierówność Feffermana dla funkcji analitycznych)
A classical result of harmonic analysis asserts that the dual space of the Hardy space H^1 on the unit circle T is the analytic space BMO(T). The purpose of the talk will be to identify …
June 6, 2024, 12:15 p.m.
Kamil Szpojankowski (Politechnika Warszawska)
Warunkowe wartości oczekiwane dla wolnych zmiennych i związki z macierzami losowymi
Badania w wolnej probabilistyce od końca lat 90 skupiają się na narzędziach pochodzących z tzw. subordynacji wolnego splotu udowodnionej przez Biane'a, która mówi, że dla $X,Y$ wolnych $E((z-X-Y)^{-1}|X)=(\omega(z)-X)^{-1}. Do tej pory nieznane były narzędzia pozwalające …
May 23, 2024, 12:15 p.m.
Paweł Hitczenko (Drexel University)
Asymptotics of a class of polynomial recurrences
We will consider sequences of polynomials defined by a recursion involving these polynomials and their first order derivatives. Recurrences like that are common in combinatorial probability and have been used and analyzed throughout the years. …
May 16, 2024, 12:15 p.m.
Soumik Dutta (University of Warsaw)
On Edge Collapse of Random Simplicial Complexes
Edge collapse, introduced in [Boissonnat, Pritam. SoCG 2020], is a process to reduce the size of a simplicial complex while preserving its homology. We study the effect of edge collapse on the Erdos-Renyi random clique …
May 9, 2024, 12:15 p.m.
Witold Bednorz (University of Warsaw)
Concentration of truncated variation for fractional Brownian motion
The talk will be about some new result that concerns bounding variation for fBM. In particular, I show some technique, due to Picard, which makes it possible to introduce some independence in studying similar questions. …