Verksamhet under hösten 1996

Sällskapet höll tre möten under hösten 1996: tisdagen den 17 september, tisdagen den 22 oktober samt ordinarie höstmöte tisdagen den 3 december. Mötena börjar klockan 18.30 i sal C i Matematikhuset. Alla, även icke-medlemmar, är varmt välkomna! Före mötena, från klockan 18.15, serveras gratis förfriskningar. Efter varje möte inbjuds alla till en eftersits med mat och dryck till självkostnadspris.

Den 17 september håller Victor Ufnarovski föredraget

Gröbner Basis and its application

Start your favorite computer algebra program and try to solve the nonlinear system of the polynomial equations. The efficiency of your program mostly depends on the efficiency of the Gröbner Basis calculations... The shortest proof of the Poincare-Birkhoff-Witt theorem is to find the Gröbner Basis... In the Mumbo-Jumbo language there are only three letters $a,b,c$ in the alphabet and every word $f$ may have one or several synonyms $g$ (we write this as $f=g.$) It is known that $$ab=c , bc=a, ca=b.$$ According the law if $f=g$ then $fh=gh$ and $hf=hg$ for arbitrary word $h.$ For example, $aa=abc=cc.$ How many different words exists in Mumbo-Jumbo? Is $ab=ba?$ To solve this it is sufficient to find the Gröbner Basis... The aim of the talk is to explain how to find and use the Gröbner Basis.

Den 22 oktober håller Bodil Branner föredraget

On complex iteration - universality of the Mandelbrot set

Short abstract: In this talk we discuss properties of dynamical systems defined through iteration of a complex analytic map, such as a polynomial or a rational function. The Mandelbrot set $M$ is a dynamically defined subset of the one parameter family of quadratic polynomials of the form $z \mapsto z^2 +c; c$ being a complex parameter. We discuss the importance of this set and the universality, showing that copies of $M$ occur in many other one parameter families of analytic maps, in particular that $M$ contains copies of itself.

En längre sammanfattning av föredraget finns här

Den 3 december håller Anders Melin föredraget

Solitoner

En sammanfattning av föredraget finns här