# Seminaria

18-01-2017 11:15
, C-11 PWr (Wydział Matematyki), sala 2.11
Mixed norm estimates for generalized radial spherical means
24-01-2019 14:15
, 603
Krystian Kazaniecki (Uniwersytet Warszawski)
Streszczenie. W latach pięćdziesiątych Gagliardo wykazał, że dla obszaru $\Omega$ z regularnym brzegiem operator śladu z przestrzeni Sobolewa $W^1_1(\Omega)$ do przestrzeni $L^1(\partial \Omega)$ jest surjekcją. Zatem naturalne jest pytanie o istnienie prawego odwrotnego operatora do operatora śladu. Petree udowodnił, że w przypadku półpłaszczyzny $\mathbb{R}x\mathbb{R}_{+}$ nie istnieje prawy odwrotny operator do operatora śladu. Podczas referatu przedstawię prosty dowód twierdzenia Petree, który wykorzystuje tylko pokrycie Whitney'a danego obszaru oraz klasyczne własności przestrzeni Banacha. Następnie zdefiniujemy operator śladu z przestrzeni Sobolewa $W^1_1(K)$, gdzie $K$ jest płatkiem Kocha. Przez pozostałą część mojego referatu skonstruujemy prawy odwrotny do operatora śladu na płatku Kocha. W tym celu scharakteryzujemy przestrzeń śladów jako przestrzeń Arensa-Eelsa z odpowiednią metryką oraz skorzystamy z twierdzenia Ciesielskiego o przestrzeniach funkcji hölderowskich.
07-11-2018 14:15
, 711/712
Topics on stochastic optimization and long-time approximation of stochastic processes
Fabien Panloup (Angers)
Stochastic optimization is a way of approximating minima of deterministic functions by a stochastic approach. I will begin my talk by some background on this topic and on the Robbins-Monro algorithm. Then, I will state some recent non-asymptotic results about Ruppert-Polyak algorithm, which is an averaged version of the Robbins-Monro algorithm. In a last part, I will briefly introduce the problem of long-time approximation of diffusion processes and its link with approximation of Gibbs distributions. I will conclude some statistical applications of these methods. This talk is based on collaborations with Sébastien Gadat and Gilles Pagès

## Dyskretna analiza harmoniczna i niekomutatywna probabilistyka

Marek Bożejko (IMPAN)
Romuald Lenczewski (WMPWr)
Wojciech Młotkowski
Janusz Wysoczański
Dane kontaktowe:
czwartek
10:15
12:00
604
30-05-2019 10:15
, 604
Analysis and probability on finite quantum groups and dual groups
Isabelle Baraquin (Université de Franche-Comté)

In this talk, we will first present a result from Diaconis, Shahshahani and Evans. Let M be a random matrix chosen from the unitary group $U(n)$ and distributed according to the Haar measure. Then, for $j\in \mathbb N$, ${\rm Tr}(M^j)$ are independent and distributed as some complex Gaussian random variables when $n\to \infty$. We will look at this type of result in the framework of finite quantum groups and then in the unitary dual group.

Referat odbędzie się w ramach projektu Polonium, współfinansowanego przez Narodową Agencję Wymiany Akademickiej (NAWA).

http://www.math.uni.wroc.pl/dgt/
18-06-2019 10:00
, 603
Nonlocal diffusion-convection equation
Diana Stan (University of Cantabria, Santander)
Joint work with Liviu Ignat.
05-06-2019 16:15
, 602
Strongly minimal compact Kähler threefolds
Jakub Gogolok
We will briefly recall basic results regarding the model theory of compact complex manifold, especially the Zilber trichotomy and some examples of strongly minimal manifolds. Next we will talk about a conjecture on strongly minimal Kähler manifolds. This conjecture implies, that odd-dimensional strongly minimal Kähler manifolds are tori. We will present the main ideas of the proof by Demailly et al. of the result saying that this holds in the case of dimension three. We will also say something about the higher-dimensional case.
16-05-2019 12:15
, 602
A) RiffleScrambler -- a memory-hard password storing function. B) Using svn repositories (installed on hera) and Mendeley in daily work with LaTeX.
Paweł Lorek (Uniwersytet Wrocławski)
A) Making a function for calculating password slow is often not enough. Such a function can be evaluated several dozen times faster on GPUs than on CPUs and even several thousand times faster on ASICs (application-specific integrated circuit). A "good" function (memory-hard) should consume lots of memory (GPUs and ASICs would not help then). We introduce RiffleScrambler -- a new family of directed acyclic graphs and a corresponding memory hard function. We prove its memory hardness in the random oracle model. B) We show how to efficiently use SVN (subversion system) -- a software versioning and revision control system (installed on hera) and Mendeley (Reference Manager) in daily work with LaTeX. In particular, we show how one can allow multiple users access our SVN repository on hera.
27-05-2019 17:15
, 604
Some twisting around the Cantor space
A twisted sum of Banach spaces $X$ and $Y$ is another space $Z$ containing $Y$ as a subspace such that $Z/Y = X$. In this talk we study the behaviour of twisted sums in which $X$ is a $C(K)$-space, using techniques from Topology and Functional Analysis. Most of the action will take place in the space of continuous functions on the Cantor space.