Organizatorzy

prof. dr hab. Rafał Latała

Informacje

czwartki, 12:15 , sala: 3160

Strona domowa

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

Lista referatów

10 kwietnia 2025 12:15
Adam Osękowski (Uniwersytet Warszawski)
Inequalities for a nonnegative submartingale and the nondecreasing component coming from the Doob-Meyer decomposition (Nierówności dla nieujemnego podmartyngału i składowej niemalejącej z rozkładu Dooba-Meyera)
Dowolny nieujemny podmartyngał X możemy przedstawić w postaci sumy M+A, gdzie M jest lokalnym martyngałem startującym z zera, a A jest procesem niemalejącym. W trakcie odczytu zajmiemy się optymalnym porównaniem p-tych norm procesów X i …
3 kwietnia 2025 12:15
Rafał Latała (University of Warsaw)
Upper bound on the injective norm of sums of Gaussian random tensors via the PAC Bayesian lemma (after I.Aden-Ali) (Upper bound on the injective norm of sums of Gaussian random tensors via the PAC Bayesian lemma (after I.Aden-Ali))
We will discuss a recent result of Ishaq Aden-Ali (On the Injective Norm of Sums of Random Tensors and the Moments of Gaussian Chaoses, arXiv:2503.10580) and show how the PAC-Bayesian lemma (a simple consequence of …
27 marca 2025 12:15
Maud Szusterman (Uniwersytet Warszawski)
Revisiting Banaszczyk's 5K-theorem (Revisiting Banaszczyk's 5K-theorem)
Banaszczyk's 5K-theorem is an important result in combinatorics. It states that in any dimension n, given any finite sequences of vectors u_1, ... , u_t taken from the unit ball B_2^n , and given any …
20 marca 2025 12:15
Jacek Jakimiuk
Stability of Khintchine inequalities with optimal constants (Stability of Khintchine inequalities with optimal constants)
We give a strengthening of the classical Khintchine inequality between the second and the $p$-th moment for $p \ge 3$ with optimal constant by adding a deficit depending on the vector of coefficients of the …
6 marca 2025 12:15
Eli Putterman (Tel Aviv University)
Small-ball probabilities for mean widths of random polytopes (Small-ball probabilities for mean widths of random polytopes)
The classical theory of random polytopes addresses questions such as computing the expectation or variance of geometric parameters associated to a random polytope (e.g., volume, number of facets, or mean width); more recent theory also …
27 lutego 2025 12:15
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 …
16 stycznia 2025 12:15
Adam Osękowski (Uniwersytet Warszawski)
Two-weight inequalities for certain dyadic operators (Nierówności dwuwagowe dla pewnych diadycznych operatorów)
Będą nas interesować pewne szczególne klasy operatorów martyngałowych, które można postrzegać jako dyskretne analogi klasycznych operatorów analizy harmonicznej: całek singularnych i potencjałów Riesza. Podamy charakteryzację dwuwagowych oszacowań w L^p dla tych obiektów, wyrażoną w języku …
19 grudnia 2024 12:15
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. …
12 grudnia 2024 12:15
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 …
28 listopada 2024 12:15
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 …
21 listopada 2024 12:15
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. …
14 listopada 2024 12:15
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 …
7 listopada 2024 12:15
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.
31 października 2024 12:15
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 …
17 października 2024 12:15
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 …