Göm menyn

# Matematiska kollokviet

Organiseras av Anders Björn, Milagros Izquierdo, Vladimir Kozlov och Hans Lundmark.

Du kan få ett dynamiskt uppdaterat schema till din dator eller smartphone från Google Calendar – se Smartphoneinstruktioner.

## Onsdag 2 maj 2018, Armen Asratian, MAI

Talare: Armen Asratian, MAI

Titel: A localization method in Hamiltonian graph theory

Tid och plats: Onsdag 2 maj 2018,  Hopningspunkten, 13.15–14.15

Sammanfattning: TBA

## Onsdag 9 maj 2018, Cyril Tintarev, Uppsala universitet

Talare: Cyril Tintarev, Uppsala universitet

Titel:  Functional-analytic theory of defect of compactness

Tid och plats: Onsdag 9 maj 2018,  Hopningspunkten, 13.15–14.15

Sammanfattning: There are many important  embeddings of functional spaces that are not compact, but, instead, every bounded sequence has a subsequence with a well-structured defect of compactness (a difference between the sequence and its limit). The primary example is the Sobolev embeddings on Euclidean space. The structure of the defect of compactness is defined relatively to a group G of linear isometries on the space. If G is rich enough, then the defect of compactness is a countable sum of "elementary concentrations" of the form $g_kw$, $g_k\in G$, with the "blowup" sequences $g_k$  acting in a decoupled manner, $g_k^{-1}\tilde g_k\rightharpoonup 0$, which corresponds in applications to terms differently scaled or with asymptotically disjoint supports. In general, such structure exists if the embedding is co-compact relative to the group G - a non-trivial property similar to, but weaker than compactness, satisfied in particular, by embeddings of Besov and Triebel-Lizorkin spaces relative to the group of translations and dilations.Other examples include Strichartz embeddings, Moser-Trudinger-(-Yudovich-Peetre) embeddings, and embeddings on Sobolev type on Riemannian and sub-Riemannian manifolds. This functional-analytic approach generalizes the concentration-compactness method developed in the 1980's in the context of calculus of variations.

## Onsdag 16 maj 2018, Nageswari Shanmugalingam, MAI och University of Cincinnati, USA

Talare: Nageswari Shanmugalingam, MAI och University of Cincinnati, USA

Titel:  Geometric and analytic aspects of infinity-Poincaré inequalities

Tid och plats: Onsdag 16 maj 2018,  Hopningspunkten, 13.15–14.15

Sammanfattning: The study of absolute minimizing Lipschitz extensions and infinity-harmonic functions in the Euclidean setting was initiated by Aronsson, Crandall and Evans, and is of great interest now, with optimal regularity of solutions yet open. In the metric setting, and indeed even in the weighted Euclidean setting, studies of such solutions are possible under certain conditions on the metric space. One condition is the existence of infinity-Poincaré inequality. In this talk we will discuss this inequality, and a geometric and analytic characterizations of this inequality.

## Onsdag 30 maj 2018, Nathan Reading, North Carolina State University, USA

Talare: Nathan Reading, North Carolina State University, USA

Titel:  TBA

Tid och plats: Onsdag 30 maj 2018,  Hopningspunkten, 13.15–14.15

Sammanfattning: TBA

## Onsdag 13 juni 2018, German Zavorokhin, Steklov Math. Institute, St. Petersburg, Ryssland

Talare: German Zavorokhin, Steklov Math. Institute, St. Petersburg, Ryssland

Titel: TBA

Tid och plats: Onsdagen 13 juni 2018, Hopningspunkten, 13.15–14.15

Sammanfattning: TBA

Sidansvarig: milagros.izquierdo@liu.se
Senast uppdaterad: Thu Apr 12 15:39:12 CEST 2018