Join us for coffee and tea at 15.30 p.m.
Tuesday, July 1st 2014
Professor Rafael Ortega
Periodic solutions of the forced pendulum: from existence to stability
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:
The University of Groningen Faculty of Science and Engineering has won the very first NNV Diversity Award. The Netherlands Physics Association (NNV) has established the award for physics institutions that best put into practice an open diversity policy...
Two promising UG academics, Dr Michael Lerch and Sanne van Dijk, will be able to conduct research at top institutes abroad for two years thanks to the Rubicon programme organized by the Netherlands Organisation for Scientific Research (NWO).
His opponent was fourfold world champion Alexander Schwarzman. Boomstra, who studies Physics at the University of Groningen, also won the title in 2016.