University of Groningenfounded in 1614  -  top 100 university

# Colloquium Mathematics, Professor Rafael Ortega

01 July 2014

 Date: Tuesday, July 1st 2014 Speaker: Professor Rafael Ortega Room: 5161.0293 (Bernoulliborg) Time: 16.00

Title: Periodic solutions of the forced pendulum: from existence to stability

Abstract:

Consider the equation $$x''+\beta \sin x=f(t)$$ where $f(t)$ is a periodic forcing. This simple model is a good laboratory to test some global methods in Nonlinear Analysis. Traditionally the existence of periodic solutions is discussed using tools coming from Topology and Calculus of Variations. In this talk we will try to adapt these tools for the study of the stability of these solutions. The results will be of the type "For almost every forcing $f(t)$..." and the notion of set of measure zero in a space of infinite dimensions will play an important role.

Colloquium coordinators are Prof.dr. A.C.D. van Enter (e-mail : A.C.D.van.Enter@rug.nl) and Dr. A.V. Kiselev (e-mail: a.v.kiselev rug.nl )

http://www.rug.nl/research/jbi/news/colloquia/mathematics-colloquia/

## More news

• 11 June 2021

### Prof. Slotboom co-applicant in awarded ZonMw project application

Prof. Slotboom co-applicant in awarded ZonMw project application

• 02 June 2021

### Partial solar eclipse on 10 June can be seen with free eclipse glasses

On Thursday 10 June, a partial solar eclipse will be visible in the Netherlands. The eclipse will start at 11.21 a.m., with a peak at 12.27 p.m. At 1.36 p.m., the eclipse will be over. Eclipse glasses will be handed out at five locations.

• 31 May 2021

### Nederlandse zonneauto teams: samen tegen klimaatverandering

De vier Nederlandse solar teams (Delft, Eindhoven, Groningen, Twente) slaan de handen ineen tegen klimaatverandering De studententeams bouwen hun eigen zonneauto’s en ontwikkelen innovaties voor een duurzamere toekomst, maar zien tegelijkertijd dat...