| Title | Quasi-stationarity and exit times for a size-dependent branching process |
| Speaker | Professor Göran Högnäs Åbo Akademi University Finland |
| Time | 3:00-4:00 p.m. |
| Place | PHY 118 |
| Sponsor | Professor A. Mukherjea |
Abstract
A size-dependent branching model of the evolution of a single species population is introduced. The short-term behavior mimics the corresponding deterministic dynamical system very closely, but the branching model hits 0 eventually, i.e., the population goes extinct in contrast with the deterministic model which remains positive at all times. It turns out that the so-called quasi-stationary distribution (q.s.d.) of the branching model gives the right asymptotics. The q.s.d. approximates the attracting limit cycles of the deterministic system. I will also discuss some results, mainly due to Klebaner and Liptser, on the order of magnitude of the extinction times.
| Title | Some Problems on the Chromatic Number of Infinite graphs |
| Speaker | Peter Komjath Eotovos University Budapest, Hungary |
| Time | 4:00-5:00 p.m. |
| Place | PHY 120 |
| Sponsor | Professor V. Totik |
Abstract
We survey some problems concerning the chromatic number of infinite graphs. A recent negative solution to Taylor's problems will be sketched.
Please direct questions to mthmaster@nosferatu.cas.usf.edu.
Last updated: 22-Nov-2005.
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