v 52, 2006 - 01, 2007

Seminarium i beräkningsvetenskap

Onsdagen den 20 december kl 14.15 (OBS tiden) talar professor Axel Ruhe, Nada, KTH.

Title: Rational Krylov for real pencils with complex eigenvalues.

Abstract: Real matrix pencils with complex eigenvalues are quite common in applications. They correspond to dynamical systems with damped oscillating solutions. It is  important to compute a real reduced model for such a system. A real double shift variant of Rational Krylov was developed already in 1993, but it is not until this Summer, that we have got any numerical experience and theoretical understanding of this algorithm. Results from the thesis of Henrik Olsson and the diploma works by Zenon Matthews and Henrik Holst will be reported.

Lokal: Glashuset

Välkomna!

Lars Eldén

Disputation i beräkningsvetenskap

Fil lic Lennart Simonsson försvarar sin doktorsavhandling  torsdagen den 21 december kl 10.15.

Titel: Subspace Computations via Matrix Decompositions and Geometric Optimization.

Fakultetsopponent är professor Axel Ruhe, Nada, KTH.

Sammanfattning av avhandlingen finns på URL:
http://www.mai.liu.se/~lesim/theabstract.pdf

Plats: Glashuset.

Välkomna!

Lars Eldén
 

Presentation av examensarbete

Onsdagen den 20 december kl 13.15 presenterar Gabriel Bartolini sitt examensarbete.

Title:  On Poincaré´s Uniformization Theorem.

Abstract: A compact Riemann surface can be realized as a quotient space $\mathcal{U}/\Gamma$, where $\mathcal{U}$ is the sphere $\Sigma$, the euclidian plane $\mathbb{C}$ or the hyperbolic plane $\mathcal{H}$ and $\Gamma$ is a discrete group of automorphisms. This induces a covering $p:\mathcal{U}\rightarrow\mathcal{U}/\Gamma$.
For each $\Gamma$ acting on $\mathcal{H}$ we have a polygon $P$ such that $\mathcal{H}$ is tesselated by $P$ under the actions of the elements of $\Gamma$. On the other hand if $P$ is a hyperbolic polygon with a side pairing satisfying certain conditions. The group $\Gamma$ generated by the side pairing is discrete and $P$ tesselates $\mathcal{H}$ under $\Gamma$.

Plats: Glashuset

Välkomma!

Milagros Izquierdo

Nästa nummer

Torsdagen den 11 januari 2007 utkommer nästa nummer av Lite Mat.

God Jul och Gott Nytt År

Merry Christmas and a Happy New Year

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