v 52-01, 06

Matematiska Kollokviet

Wednesday 11 Januari 2006, 13.15-14.15 talar Natan Krugljak, Luleå universitet, om

Title: Open Property of Invertibility of Operators on Interpolation Scales

Abstract: A remarkable theorem of Shneiberg extended to complex interpolation scalee the well-known fact that the set of bounded invertible operators acting on a Banach space is open in the space of all operators. After that this property has been intensively studied in the literature. Recently in joint paper with M.Milman we derived a unified approach to Shneiberg's theorem that works for complex, real and many others methods of interpolation. I plan to discuss known results and their proofs, give some examples and formulate several problems and conjectures.

Wednesday 18 Januari 2006, 13.15-14.15,  talar Sten Kaijser, Uppsala universitet, om

Title: An orthogonal polynomial basis for a Hilbert space of analytic functions in a strip

Abstract:  A few years ago I amused myself by calculating the orthogonal polynomials with respect to the weight $\frac{1}{2\cosh\frac{\pi x}{2}}$. In my calculations I used some simple operators, and these opertors more or less forced me to investigate another system of polynomials that turned out to be orthogonal with respect to the Poisson kernel for a strip. Both these sets turned out to have very simple generating functions and also other interesting properties, in particular they were well adapted to the so called  umbral calculus, developed by Gian-Carlo Rota and his students. This connection was found by my graduate student Tsehaye K. Araaya and was developed in his thesis which was presented in June 2003. I will also present some new results concerning these polynomials.

Wednesday 25 Januari 2006, 13.15-14.15, Glashuset talar Hans Lundmark, MAI.

Plats: Glashuset.

Välkomna!

Armen Asratian, Milagros Izquierdo, Vladimir Kozlov, Stefan Rauch-Wojciechowski

Nyheter 2006 - tjänsteresor

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I Stockholm införs trängselskatt för bil den 3 januari. Avgiften är 10, 15 eller 20 kr och gäller vardagar kl 06:30-18:29. Om du kör privatbil måste du själv betala detta i en 7-elevenbutik eller Pressbyrån. Använder du dig av hyrbil så är den utrustad med transponder och du behöver själv inte betala något. På Vägverket kan du läsa mera  http://www.vv.se/templates/page3____10911.aspx . Ersättning för trängselskatt är skattepliktig.

/Theresia

God Jul och Gott Nytt År 2006 till alla läsare

A Merry Christmas and a Happy New Year 2006 to all of you

Material till Lite Mat lämnas till Bodil Stavklint senast torsdagar kl 08.00.
Linköpings universitet, 581 83 Linköping
Tel 013-281000, Fax 013-100746
E-mail: litemat@mai.liu.se