ARISTOTLE UNIVERSITY OF THESSALONIKI

DEPARTMENT OF MATHEMATICS

DIVISION OF MATHEMATICAL ANALYSIS

Tel. 2310 997906, Fax 2310 997945

Organizing Committee:

D.Betsakos

I. Gasparis

Seminar Room: 3rd floor in the building of the School of Sciences

The seminar takes place every Tuesday 11-12 a.m. (unless otherwise stated)

This year the Seminar is dedicated to the memory of Nikos Danikas.

Alfonso Montes-Rodriguez,

Universidad de Sevilla

"The extremal behavior of Volterra operator"

Abstract: We will show that the Volterra operator

does not satisfy the Kreiss matrix theorem

that gives a bound on the norm of the resolvent

of a matrix on finite-dimensional spaces.

October 12, 2004

Loukas Grafakos,

University of Missouri, U.S.A.

"Carleson's theorem on the a.e. convergence of Fourier series: a new approach".

October 14 (Thursday 11-12a.m.), 2004

Oscar Blasco,

University of Valencia, Spain

"Embedding theorems for spaces of analytic functions"

October 19, 2004

Antonis Bisbas,

Technological Educational Institute of West Macedonia

"Coin – tossing measures and their Fourier transforms"

October 26, 2004

No talk today because of Thessaloniki's holiday.

November 2, 2004

G. Paouris,

University of Crete

"Volume concentration on the balls of the Schatten trace class".

November 2, 2004, 12-1 p.m.

T. Carroll,

National University of Ireland, Cork

"Harmonic measure in parabola-shaped regions in $R^n$".

November 9, 2004

Ap. Giannopoulos,

University of Athens

"0-1 polytopes with many faces".

November 16, 2004

Themis Mitsis,

University of Crete

"Dimension-free bounds for the maximal function associated to convex

bodies: a new proof".

November 23, 2004

Stanislav Shkarin,

Moscow State University, Russia

"On supercyclicity and related properties of integral operators".

November 30, 2004

Matti Vuorinen,

University of Helsinki, Finland

"Teichmuller's extremal ring problem"

Abstract. An algorithmic solution to Teichm\"uller's

well-known extremal ring problem is presented. The

results are based on joint work of the speaker with Ville Heikkala.

December 14, 2004

Ioannis Platis

University of Durham, U.K.

"Complex hyperbolic Kleinian groups"

Abstract

Let $\pi_1$ be the fundamental group of a closed surface $\Sigma$ of genus $g>1$. We consider all discrete, faithful, geometrically finite and purely loxodromic representations of $\pi_1$ into ${\rm SU}(2,1)$, (the triple cover of) the group of holomorphic isometries of the complex hyperbolic space ${\bf H}^2_\C$ and we wish to trace the analytic and geometric properties of their space $\mathcal{Q_\C}$, the \textsl{complex hyperbolic quasi-Fuchsian space}. Up to now, little is known about the structure of this space and to describe it explicitely is considered one of the fundamental problems in complex hyperbolic geometry (the holy grail!). The first step towards this direction is to prove that given a discrete, faithful, geometrically finite and purely loxodromic representation $\rho_0$ of $\pi_1$, can we find an open neighbourhood of $\rho_0$ comprising representations with these properties. We show that this is indeed the case when $\rho_0$ preserves a totally real Lagrangian plane. This deduces immediately that $\mathcal{Q}_\C$ contains open sets of maximal dimension $16g-16$.

December 21, 2004

Grigoris Pavliotis

Imperial college, London, U.K.

Title: "Modulation Equations: Stochastic Bifurcation in Large Domains"

Abstract

We consider the stochastic Swift-Hohenberg equation on a large domain

near its change of stability. We show that, under the appropriate

scaling, its solutions

can be approximated by a periodic wave, which is modulated by the

solutions to a stochastic Ginzburg-Landau equation. We then proceed to show that this

approximation also extends to the invariant measures of these equations.

Joint work with D. Bloemker and M. Hairer.

January 11, 2005

Ioannis Gasparis

Aristotle University of Thessaloniki

Title: Operators on C[0,1] preserving copies of asymptotic l_1 spaces.

Michel Marias

Aristotle University of Thessaloniki

Title: "Srtrongly singular multipliers on Riemannian manifolds".

February 22, 2005

Vagia Vlachou

University of Crete

Title: "Universal functions on non-simply connected domains".

March 1, 2005

No seminar today.

A meeting of the organizing committee of the

11th Panhellenic Mathematical Analysis Conference will take place.

The 11th Panhellenic Mathematical Analysis Conference will take palce in Thessaloniki in May 2006.

March 8, 2005

Andreas Tolias

University of Crete

Title: "Hereditarily indecomposable Banach spaces"

March 22, 2005

Simos Ichtiaroglou

Department of Physics, Aristotle University of Thessaloniki

March 29, 2005

Aristidis Katavolos

University of Athens

Title: "Subspaces of L_2(R) invariant by pairs of semigroups".

April 5, 2005

Georgios Eleftherakis

University of Athens

Title: "Decomposition of reflexive modules over maximal

self-adjoint abelian operator algebras".

April 12, 2005

Irene Deliyanni

Athens University of Economics and Business

Title: "Diagonal operators on hereditarily indecomposable

Banach spaces".

April 19, 2005

A. Vidras

University of Cyprus

Title: "Integral representations of analytic functions by Carleman formulae".

May 17, 2005

N. Charalambakis

Aristotle University of Thessaloniki

May 24, 2005

G. Georganopoulos

Aristotle University of Thessaloniki

Jume 28, 2005

Eva Gallardo-Gutierrez

University of Zaragoza, Spain

Title: "Composition Operators on Hardy spaces of a simply connected domain"

Abstract:

For
any simply connected domain $\Omega$, we prove that a Littlewood type
inequality satisfied by the symbol $\varphi$ is necessary for boundedness of
the composition operator $C_{\varphi}$ on the Hardy spaces $H^p(\Omega)$,
$1\leq p<\infty$, whenever the symbol $\varphi$ is finitely-valent. Of
course, the corresponding "little-oh" condition held by $\varphi$ is
also necessary for the compactness of $C_{\varphi}$. Nevertheless, it is shown
that such inequality is not sufficient for characterizing bounded composition operators even induced
by univalent symbols. Furthermore, such inequality is no longer necessary if we
drop the extra assumption on the symbol of being finitely-valent. In
particular, this solves a question posed by Shapiro and Smith and shows a
striking link between the geometry of the underlying domain and the symbol inducing the composition
operator in $H^p(\Omega)$, $1\leq p<\infty$.

(Joint work with María J. González y Artur Nicolau)

The Analysis Seminar in 2003-2004.

The Analysis Seminar in 2002-2003.(in Greek)

The Analysis Seminar in 1992-2002. (in Greek)