Events at Physics |
Events on Tuesday, March 3rd, 2009
- R. G. Herb Condensed Matter Seminar
- Radio Frequency Spectroscopy in Ultra-cold Fermi gases Undergoing BCS-BEC Crossover
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Yan He, University of Chicago
- Abstract: In recent years, ultra-cold atoms opened an exciting new direction of condensed matter physics. Radio frequency spectroscopy provides an important tool to understand energy gap and quasi-particle dispersion in ultra-cold Fermi gases. Here we present a systematic study of the RF spectra of Fermi gases in the BCS-BEC crossover. We discuss the effects of traps, population imbalance, final state interactions over the entire range of temperatures and compare theory with experiment. The result shows that this broad range of phenomena can be accommodated within the BCS-Leggett description of BCS-BEC crossover.
- Host: Mark Friesen
- Chaos & Complex Systems Seminar
- Place; It's complicated: Nagas in the Himalaya
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Chris Limburg, UW Department of Geography
- Abstract: Place is more complex than we think it is. Places--so often taken for granted--shape our environment, society, and imagination. This talk will elaborate the ways that we think about places. It will address questions like: what is a place, exactly? How does thinking about places help us understand our world? And: isn't place just a location in inert space? In answering these questions, I will argue for the importance of using place as a lens as well as a site. Examining place epistemologically and ontologically, this talk will demonstrate the usefulness of thinking geographically about our fragmented relationship with the environment. With a deeper sense of place we can engage environment, society, and self as emergent despite their seeming fixity. The talk will first outline the debates concerning the nature of place in geography. Then it will use the example of naga nature spirits in the Kathmandu valley to illustrate the complexity of place.
- String Theory Seminar
- An Inverted Mass Hierarchy for Exciting Dark Matter
- Time: 2:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Andrew Frey, McGill University
- Astronomy Colloquium
- The Origins and Evoluation of Weak MB II Quasar Absorption Line Systems
- Time: 3:30 pm
- Place: 6515 Sterling Hall
- Speaker: Anand Narayanan, UW Astronomy Dept
- Abstract: Among the various class of intervening quasar absorption line systems, the origin(s) of weak Mg II absorbers have remained a mystery. It is not well understood what kind of astrophysical structures produce these absorption systems. I will present results from UV and optical spectroscopic surveys of ~100 quasar sight lines, which has yielded a full census of this absorber population over a significant fraction of the history of the universe. Based on the results we extend the proposition that a substantial fraction of these absorbers could be tracing gas at the galaxy-IGM interface, analogous to Galactic high-velocity cloud structures.<br>
- Host: UW Madison
- String Theory Seminar
- A Tour of Flux Compactification Dynamic
- Time: 4:30 pm
- Place: 5280 Chmaberlin Hall
- Speaker: Andrew Frey McGill