Events at Physics |
Events During the Week of February 8th through February 15th, 2009
Monday, February 9th, 2009
- Plasma Physics (Physics/ECE/NE 922) Seminar
- News from the ASDEX Upgrade tokamak Programme
- Time: 12:05 pm - 1:05 pm
- Place: 3345 Engineering Hall
- Speaker: Professor Hartmut Zohm, Max-Planck Intsitut fuer Plasmaphysik, Garching, German7
- Theory/Phenomenology Seminar
- Phase-space Structure of the Milky Way's Dark Halo
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Leanne Duffy, Los Alamos National Laboratory
- Abstract: Abstract: The evolution of cold dark matter in phase-space inevitably leads to high density regions in physical space, known as caustics. The significance of these high density structures is a current topic of debate. One interesting possibility is presented by the caustic ring model, which describes the accretion of dark matter onto galactic halos. I explain the formation of dark matter caustics, present an overview of the caustic ring model and predictions of the model for the Milky Way halo. The resulting dark matter flows and overdensities may have important consequences for both direct and indirect dark matter detection experiments.
- High Energy Seminar
- Joint HEP-NPAC Seminar
- Latest Results from MiniBoone
- Time: 4:00 pm
- Place: 4274 Chamberlin: (Coffee and Cookies at 3:45 pm
- Speaker: Chris Polly, University of Illinois Urbana-Champaign
- Host: Karsten Heeger
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Joint NPAC Forum/HEP Seminar
- New oscillation results from MiniBooNE
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Chris Polly, University of Illinois Urbana-Champaign
- Abstract: In June 2007, MiniBooNE published results for a search for electron flavor neutrinos appearing in a predominantly muon neutrino beam. Although no excess of events was observed at an L/E consistent with a simple mixing interpretation of LSND, a > 3 sigma excess was observed at low energy. In the intervening time, MiniBooNE has acquired 3.3e20 POT delivered with the horn-focusing positively charged pions to create a predominantly antineutrino beam. The results from the recently unblinded nuebar appearance search will be discussed along with work that has transpired over the last year in understanding the low energy excess.
- Host: Karsten Heeger & Mat Herndon
Tuesday, February 10th, 2009
- Special Plasma Seminar
- Measurements of Fast Ion Profiles During High Harmonic Fast Wave Heating on NSTX
- Time: 12:00 pm - 1:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Deyong Liu, University of California/Irvine
- Chaos & Complex Systems Seminar
- A brief survey of financial derivatives
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Don Hester, UW Department of Economics
- Abstract: Financial derivative contracts have exploded in varietyand complexity since the early 1970s. I will describe and interpret the basic "plain vanilla" derivatives, forward, futures, and option contracts, in the first half of this talk. Then I will explore the reasons for the proliferation of new derivatives, interpret several of them, and comment on how they have impacted the economy.
- Astronomy Colloquium
- The Evolution of AGN in Clusters of Galaxies
- Time: 3:30 pm
- Place: 6515 Sterling Hall
- Speaker: Paul Martini, Ohio State
- Abstract: Galaxies in clusters have undergone profoundly different evolution relative to their counterparts in the field. I will present new results that show the same holds true for the supermassive black holes at the centers of cluster galaxies. While luminous AGN are nearly nonexistent in local clusters, they are comparatively common in clusters about z=0.5.<br>
Furthermore, the rate at which cluster AGN have shut off from high redshift to the present day is substantially faster than the decline in the space density of field AGN. The evolution of the cluster AGN population therefore appears to mirror the evolution of cluster star-forming galaxies, as well as suggest that AGN downsizing has an<br>
environmental dependence.<br>
- Host: Professor Andy Sheinis
- Astronomy Colloquium
- Astronomy/Physics Colloquium
- Science with the International X-ray Observatory
- Time: 3:45 pm
- Place: 4274 Chamberlin Hall
- Speaker: Randall Smith, Harvard Smithsonian Center for Astrophysics
- Abstract: In July 2008, the International X-ray Observatory (IXO) was announced to the astronomical community. IXO is a joint mission with participation from ESA, NASA and JAXA, superseding the US
Constellation-X mission concept. IXO is dedicated to high resolution X-ray spectroscopy, with 100 times the throughput for high resolution spectroscopy of previous X-ray missions. The baseline for IXO features a single large X-ray mirror and an extensible optical bench with a 20-25m focal length and moveable focal plane. The instruments include an X-ray wide field imaging spectrometer, a high spectral resolution non-dispersive X-ray spectrometer, an X-ray grating spectrometer, a hard X-ray imaginer and an X-ray polarimeter. I will discuss the IXO science objectives and how it will help answer the following questions: How do super-massive Black Holes grow and evolve? Does matter orbiting close to a Black Hole event horizon follow the predictions of General Relativity? What is the Equation of State of matter in Neutron Stars? How does Cosmic Feedback work and influence galaxy formation? How does galaxy cluster evolution constrain the nature of Dark Matter and Dark Energy? Where are the missing baryons in the nearby Universe? When and how were the elements created and dispersed? How do high energy processes affect planetary formation and habitability? How do magnetic fields shape stellar exteriors and the surrounding environment? How are particles accelerated to extreme energies producing shocks, jets, and cosmic rays? Wednesday, February 11th, 2009
- No events scheduled
Thursday, February 12th, 2009
- R. G. Herb Condensed Matter Seminar
- Precision Measurements of the London Penetration Depth and Pairing Symmetry in Superconductors
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Ruslan Prozorov, Iowa State University & Ames Laboratory
- Abstract: The pairing mechanism is the Holy Grail for researchers in the field of superconductivity. One of the experimentally accessible manifestations of the pairing mechanism is the structure of the superconducting gap on the Fermi surface and the corresponding behavior of low-energy quasiparticles with respect to an applied magnetic field, scattering rate, heat flow, etc. The London penetration depth is directly related to the superfluid density and, therefore, is one of the primary experimentally measurable quantities. It is also relatively easy to model for various superconducting gaps and for arbitrary scattering by using microscopic or semiclassical formalisms.
During the last 20 years, there has been remarkable progress in the development of techniques for ultra-precise measurements of the penetration depth, especially in the frequency-domain. I will briefly review the major milestones where this technique has been used--from the very first discovery of d-wave pairing in hole-doped cuprates [1] through d-wave pairing in electrondoped cuprates [2]. I will spend most of the time on today's hot topic of Fe-based pnictide superconductors for which the unconventional behavior will be demonstrated [3]. It is possible that this class of materials is one of the most complex we have ever encountered in the field of superconductivity due to complex multi-band electronic structure and substantial influence of the magnetic subsystem.
[1] W. N. Hardy et al., Phys. Rev. Lett. 70, 3999 (1993)
[2] R. Prozorov et al., Phys. Rev. Lett. 85, 3700 (2000)
[3] R. T. Gordon et al., http://arxiv.org/abs/0812.3683 - Host: Andrey Chubukov
- Atomic Seminar
- Ultracold plasma dynamics in a magnetic field
- Time: 12:00 pm
- Place: 5310 Chamberlin
- Speaker: Xianli Zhang, University of Maryland
- Abstract: Ultracold plasmas created by photoionizing a sample of laser cooled and trapped cold atoms, has extended the neutral plasma parameters by about two orders of magnitude, as the electron temperatures as low as 1 Kelvin. Previous studies focused on the study of the plasma free expansion and electron temperature evolution without a magnetic field. In this talk, I will present the first study of ultracold plasma dynamics in a magnetic field by using a newly developed time-of-flight projection imaging technique, such as plasma expansion and plasma instabilities.
- Host: Mark Saffman
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Covariance, Dynamics and Symmetries, and Hadron Physics
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Craig Roberts, Argonne National Laboratory
- Abstract: QCD's Dyson-Schwinger equations provide a continuum framework within which hadron structure and interactions can be studied. Nonperturbative, symmetry-preserving truncations exist so that model-independent predictions can be made and illustrated. Insights that this approach yields into meson and nucleon structure will be explained.
- Host: M J Ramsey-Musolf
Friday, February 13th, 2009
- Physics Department Colloquium
- Gravity on the Test Bench: Torsion Balance Renaissance
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee and cookies at 3:30 pm)
- Speaker: Jens Gundlach, University of Washington
- Abstract: In the last two decades torsion balances have been reintroduced to modern physics. We have built highly refined torsion balances to search for subtle deviations from ordinary weak-field gravity; in particular, we have tested the equivalence principle to unprecedented precision, including a test searching for non-gravitational accelerations towards dark matter. We have built special torsion balances to test the 1/r2-law of gravity for distance scales as small a few tens of micrometers. Furthermore we have measured Newton's constant with unmatched precision and have tested F=ma. We are also using our ultra-sensitive torsion balance instruments to look for stray forces that may affect the gravity wave observatories LIGO and LISA.
- Host: Heeger and Ramsey-Musolf