Join us for coffee and tea at 15.45 p.m.
Date: Tuesday, June 14th 2011
Speaker: Anne Fey (TUD)
Room: 5161.0267 (Bernoulliborg),
Limiting shapes for nonabelian sandpile growth models,
Joint work with Haiyan Liu.
On a grid, start with a pile of height n > 1 at the origin, and a pile of height h < 1 on every other grid vertex. Split every pile that has height at least 1, that is, distribute its total height equally among the neighbors. We are interested in the set S of sites where we split a pile at least once.
Depending on h, n and possibly even on the order in which we split piles, either S reaches a final size or S keeps increasing. We show that the first case occurs for h small enough and arbitrary splitting order, and we give bounds for the size of S, using similar methods as for the abelian sandpile growth model.
In the second case, our model behaves strikingly different from the abelian sandpile growth model. With the parallel splitting order, S can have a multitude of different limiting shapes. We demonstrate several of them, leaving plenty of opportunity for further research.
are Prof.dr. A.C.D. van Enter (e-mail : A.C.D.van.Enter@rug.nl) and
Dr. M.E. Dür (e-mail: M.E.Dur@rug.nl)
Een filmpje over het onderzoek van RUG-natuurkundige Bart van Wees is opgepikt door de populaire wetenschapsblogger Hashem Al-Ghaili. Via zijn Facebook site is de film in een paar dagen tijd meer dan 260.000 keer bekeken en ruim 2.100 keer gedeeld....
Mo Verhoeven van de Rijksuniversiteit Groningen en collega’s hebben ontdekt dat de jonge grutto’s deze verandering in het trekpatroon bewerkstelligen. Bijna alle volwassen vogels blijven namelijk op de trek naar Nederland trouw aan hun normale route:...
Professor emeritus Serge Daan was an inspiring biologist with a broad interest in science. He was a fellow of the Royal Society of Canada and was knighted in the Order of the Lion of the Netherlands. He was awarded several prizes and awards, including...