Events at Physics |
Events During the Week of April 26th through May 3rd, 2009
Monday, April 27th, 2009
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Particle Acceleration and Magnetic Field Amplification in Collsionless Shocks
- Time: 12:05 pm
- Place: 3345 Engineering Hall
- Speaker: Brian Reville, Max-Planck Intsitut fuer Plasmaphysik, Garching, Germany
- Special Astronomy Colloquium
- Cosmic Rays emission from active and non-active Galaxies
- Time: 3:30 pm - 5:00 pm
- Place: 4534 Sterling Hall
- Speaker: Dr. Julia Becker, Physics Institute, Gothenberg University Sweden
- Abstract: High-energy Cosmic Rays hit the Earth's atmosphere every day, with
energies of 1e9 up to more than 1e20 eV per particle. Still after almost 100 years of their discovery, the exact origin is still unknown as magnetic fields scramble the direction of Cosmic Rays. In this talk, Cosmic Ray acceleration sites in starburst and active galaxies are discussed. In addition, estimates of the high-energy photon and neutrino fluxes arising from Cosmic Ray interactions in the sources are presented. These neutral particles lead right to their production sites and can therefore be used to identify the sources of high-energy Cosmic Rays. - Host: Professor John S Gallagher
Tuesday, April 28th, 2009
- Chaos & Complex Systems Seminar
- Applications of neural networks in time-series analysis
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Adam Maus, UW Department of Physics
- Abstract: Artificial neural networks are mathematical models that emulate biological neural systems. They have been used in classification, pattern recognition, and time-series analysis. In time-series analysis, neural networks can be used for forecasting but also to determine how many and which past values are required to predict the future. Determination of this 'lag space' sheds light on the nature of the dynamics and permits development of minimal models capable of replicating the dynamics. I will highlight applications of neural networks in the real world as models that classify, forecast, and analyze data while emphasizing their use in determining the lag space.
- Astronomy Colloquium
- How Black Holes get their Kicks
- Time: 3:30 pm - 5:00 pm
- Place: 6515 Sterling Hall
- Speaker: Kelley Holley-Bockelman, Vanderbilt University
- Abstract: Finally, computer simulations can merge two black holes in full general relativity -- and the latest results reveal a big surprise: when two black holes merge, the new black hole gets a gravitational wave kick with a velocity as high as 4000 km/s. A kick this fast can send even a supermassive black hole careening out of its home galaxy. How, then, do galaxies - especially low mass ones in the early universe - retain supermassive black holes after they merge? We will explore this and other consequences of kicking black holes in this talk.
- Host: WOWSA
Wednesday, April 29th, 2009
- No events scheduled
Thursday, April 30th, 2009
- R. G. Herb Condensed Matter Seminar
- Giant Nernst Effect due to Fluctuating Cooper Pairs in Superconductors
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Andrei Varlamov, INFM & CNR, Italy, Moscow Technological University, Russia
- Abstract: A theory of the fluctuation-induced Nernst effect is developed for arbitrary magnetic fields and temperatures beyond the upper critical field line in a two-dimensional superconductor. First, we derive a simple phenomenological formula for the Nernst coefficient, which naturally explains the giant Nernst signal due to fluctuating Cooper pairs. The latter is shown to be large even far from the transition and may exceed by orders of magnitude the Fermi liquid terms. We also present a complete microscopic calculation (which includes quantum fluctuations) of the Nernst coefficient and give its asymptotic dependencies in various regions of the phase diagram. It is argued that the magnitude and the behavior of the Nernst signal observed experimentally in disordered superconducting films can be well understood on the basis of superconducting fluctuation theory.
- Host: Maxim Vavilov
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- AdS/QCD
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Misha Stephanov, U. Illinois Chicago
- Abstract: I shall describe a bottom-up approach to modeling low-energy properties of QCD using holographic duality. Chiral symmetry and its breaking, QCD sum rules as well as asymptotic scaling are simultaneously realized in such models. The simplest model of this type gives a remarkably good fit to many low energy hadronic observables.
- Host: M J Ramsey-Musolf
Friday, May 1st, 2009
- Physics Department Colloquium
- Physics in the Kitchen
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Andrei Varlamov, INFM & CNR, Italy, Moscow Technological University, Russia
- Abstract: The lecture is devoted to the description of the physical aspects of the preparation of tea, coffee, wine, turkey and spaghetti. The topics covered in the presentation will include the filtration process, heat propagation in a piece of meat, interaction of an electromagnetic field with water molecules, NMR characterization of wine quality, the origin of the kettle noise before boiling and dependence of its frequency on temperature. I will also discuss advantages of espresso over other methods of coffee preparation.
- Host: Vavilov