Events at Physics |
Events During the Week of April 19th through April 26th, 2009
Monday, April 20th, 2009
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Electron Bernstein Waves in Tokamaks, Spherical Tokamaks, Stellarators and RFPs
- Time: 12:05 pm
- Place: 3345 Engineering Hall
- Speaker: Francesco Volpe, University of Wisconsin, Dept. of Engineering Physics
- Plasma Theory Seminar
- Title to be announced
- Time: 4:00 pm
- Place: 514 ERB
- Speaker: Andrew Cole, UW-Madison, CPTC & Dept of EP
Tuesday, April 21st, 2009
- Chaos & Complex Systems Seminar
- Title to be announced
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Olga Trubetskoy, Pharmacy and Comparative Biosciences
- Astronomy Colloquium
- A Census of Baryons in Groups and Clusters of Galaxies
- Time: 3:30 pm - 5:00 pm
- Place: 6515 Sterling Hall
- Speaker: Ann Zabludoff, Univ of AZ, Steward Observatory
- Abstract: We have now discovered that intracluster stars are a significant part of the stellar baryons in galaxy clusters and groups. The detection of this previously unexplored baryonic component has consequences for the baryon budget of clusters and its relationship to the universal value obtained from WMAP observations of the cosmic microwave background radiation.
Because metals produced by intracluster stars do not need to escape from galaxies, but are instead directly injected into the intergalactic medium, the existence of this stellar population also has significant consequences for the enrichment history of the hot, X-ray-emitting, intracluster gas.
I will review our recent work characterizing the properties of
intracluster stars, as well as new constraints on missing baryons on the scales of clusters and groups, on whether it is possible to account for the high metal content of the intracluster medium, and on the mass profiles of the largest bound systems in the universe.
- Host: Professor Eric Wilcots
Wednesday, April 22nd, 2009
- Special Plasma Seminar - Dept of ECE
- Impact of Wall Conditioning on Plasma Parameters in the TJ-II Stellarator
- Time: 12:00 pm
- Place: 3345 Engineering Hall
- Speaker: Francisco Tabares, CIEMAT-Madrid, Spain
Thursday, April 23rd, 2009
- R. G. Herb Condensed Matter Seminar
- BCS-BEC Crossover in Ultracold Atoms: Quantum Fluctuations and Vortices
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Mohit Randeria, Ohio State University
- Abstract: I will first introduce the problem of the BCS-BEC crossover in a Fermi gas with arbitrary interactions and describe the progress in realizing these ideas in experiments with ultracold atomic gases. I will then discuss three questions: (1) How quantum fluctuations about the mean field state impact observable properties in the crossover; (2) How the vortex and core states evolve from the BCS to the BEC limits; (3) Why the most strongly interacting regime at unitarity leads to the most robust superfluid in the entire crossover.
- Host: Andrey Chubukov
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Poincare Invariant Three-Body Scattering
- Time: 1:30 pm - 2:25 pm
- Place: 4274 Chamberlin
- Speaker: Charlotte Elster, Ohio University, Athens
- Abstract: An enormous effort has been made to understand and model the nuclear force. The next step is to apply those models in an environment where three (or four) nucleons interact with each other and thoroughly test underlying assumptions of nuclear physics.
Traditionally three-nucleon calculations are carried out by solving Faddeev equations in a partial wave truncated basis, working either in momentum or coordinate space. We solve them directly as function of vector variables. The key advantage of our approach lies in its applicability at higher energies, where special relativity is expected to become relevant. We investigate relativistic three-boson scattering in the framework of Poincare invariant quantum mechanics. The main point here is the construction of unitary irreducible representations of the Poincare group, both for noninteracting and interacting particles. For three-body scattering the Faddeev scheme is reformulated relativistically.
Comparison of scattering observables obtained from relativistic and non-relativistic calculations based on simple Yukawa-type interactions lead to observations that should be relevant for more sophisticated interactions. These comparisons do not involve taking non-relativistic limits. Instead relativistic and non-relativistic three-body calculations are compared that contain interactions fitted to the same two-body data. All of the observed differences result form the different ways in which the two-body dynamics appears in the three-body problem. - Host: Baha Balantekin
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Searching for exoearths and measuring the acceleration of the universe with femtosecond laser frequency combs
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Andrew Szentgyorgyi, Harvard CFA
- Abstract: Octave-spanning, mode locked femtosecond laser frequency combs convert
the most precise instrument available today - the atomic clock - to the frequency domain, providing an equally precise yardstick for wavelength calibration, potentially 1:10^15. Precision at this level enables astronomical radial velocity measurements to 1 cm/sec over decadal time scales. This capability will make it possible to search for earth-like planets orbiting solar type-stars in the habitable zone and to measure the expansion of the universe directly, as well as to explore the local distribution of dark matter and to search for variations of fundamental constants over cosmological time scales. I discuss the techniques, status and potential of this instrumentation as well as ongoing and future observational programs in pursuit of these scientific objectives. - Host: Francis Halzen
Friday, April 24th, 2009
- Physics Department Colloquium
- Let's go Skating... and do some Physics on the Ice
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Charlotte Elster, Ohio University
- Abstract: Skating is fun! Figure skating is fun, great exercise and beautiful to watch. Though I skated as a child on frozen ponds, I started figure skating only a few years ago. This talk will discuss slippery ice and how our blades work. Then the intricate interplay of linear and angular momentum that characterizes the beauty and challenge of figure skating will be explained with selected examples. Above all I want to share my love for the sports while looking at it through the lens of a physicist.
- Host: Balantekin