Events at Physics |
Events During the Week of October 19th through October 26th, 2008
Monday, October 20th, 2008
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Magnetic Turbulent Reconnection
- Time: 12:05 pm
- Place: 1227 Engineering Hall
- Speaker: Alexander Lazarian, University of Wisconsin. Dept of Astronomy/Physics
- Theory/Phenomenology Seminar
- Dark Matter Annihilation Modes
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Tom Weiler, Vanderbilt University
- Host: Vernon Barger
- High Energy Seminar
- Search for High-Mass Resonances in CDF Dimuon Data
- Time: 4:00 pm - 5:00 pm
- Place: 4274 Chamberlin: Coffee and Cookies at 3:45 pm
- Speaker: Chris Hays, University of Oxford
- Host: Matthew Herndon
- Plasma Theory Seminar
- Title to be announced
- Time: 4:00 pm
- Place: 514 ERB
- Speaker: Thomas Jenkins, UW-Madison, Dept of Physics/Plasma
Tuesday, October 21st, 2008
- Chaos & Complex Systems Seminar
- Gender, power and peacemaking in Africa
- Time: 12:05 pm
- Place: 4274 Chamberlin (Refreshments will be served)
- Speaker: Aili Mari Tripp, UW Departments of Political Science and Women's Studies
- Abstract: The presentation will look at why almost all post-conflict countries in Africa have double the rates of legislative representation of women compared with countries that have not undergone conflict. Moreover, these countries tend to have been more open to passing legislation and making constitutional changes relating to women's rights. In my talk, I explain why Rwanda has the highest rates of legislative representation of women in the world (49% of all seats are held by women) and why Liberia has the first elected woman president in Africa. The talk examines how and why the end of major civil conflicts, especially since the 1990s from South Africa to Namibia, Mozambique, Rwanda, Burundi, Liberia and Sierra Leone, opened up new opportunities for women activists. I discuss the broader international context of these changes, changing gender relations during civil war, and the role of women1s movements. The talk is based on both comparative research across Africa as well as fieldwork in Uganda, Liberia and Angola.
- Astronomy Colloquium
- The SWIFT Bat Hard X-ray Survey- A New Window on the Local AGN Universe
- Time: 3:30 pm
- Place: 6515 Sterling Hall
- Speaker: Richard Mushotsky, Goddard Space Flight Center/NASA
- Abstract: The Swift Burst and Transient telescope (BAT) has surveyed the entire sky for the last 3.5 years obtaining the first sensitive all sky survey of the 14-195 keV sky. At high galactic latitudes the vast majority of the detected sources are AGN. Since hard x-rays penetrate all but Compton thick obscuring material (Column densities of 1.6E24 atms/cm2) this survey is unbiased with respect to obscuration, host galaxy type, optical , radio or IR properties. We will present results on the broad band x-ray properties, the nature of the host galaxies, the luminosity function and will discuss a few of the optical, IR and x-ray results in detail.<br>
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Wednesday, October 22nd, 2008
- No events scheduled
Thursday, October 23rd, 2008
- R. G. Herb Condensed Matter Seminar
- Spinons and triplons in a spatially anisotropic triangular lattice antiferromagnet
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Oleg Starykh, University of Utah
- Abstract: Many of the frustrated magnetic materials are characterized by pronounced spatial anisotropy of the exchange interaction between spins. I will argue that one can successfully exploit this fact and approach the problem of frustrated magnetism from a one-dimensional point of view, by treating frustrated inter-chain interactions as a perturbation to a system of decoupled chains.
As a warm-up, I present a problem of a single Heisenberg chain subject to asymmetric Dzyaloshinskii-Moriya interaction and external magnetic field. Rather unexpectedly, the system is found to possess a field-induced long-range order of the SDW type.
I then proceed with the main focus of my talk: static and dynamic properties of the spatially anisotropic triangular lattice antiferromagnet, with inter-chain diagonal exchange J' much weaker than the intrachain exchange J. Despite retaining magnetic long range order in its ground state, this spatially anisotropic antiferromagnet exhibits very unusual dynamic response (broad continuum) in a wide range of energy and momentum. I will show that the spectrum of excitations from moderate to high energies is composed of incoherent continuum, arising from the one-dimensional spinons of individual spin chains, and a sharp dispersing peak, due to coherently propagating "triplon" bound states of two spinons. I will present a direct and parameter-free comparison of the calculated dynamical spin correlations with inelastic neutron measurements on Cs2CuCl4. - Host: Chubukov
- Graduate Introductory Seminar
- Condensed Matter Theory Intro Seminar
- Time: 5:30 pm - 6:30 pm
- Place: 2223 Chamberlin Hall
- Speaker: Condensed Matter Theory Group, Physics Dept
- Abstract: Introductory Seminar for first year Grad Students (others welcome)
- Host: Condensed Matter Theory Group
Friday, October 24th, 2008
- Physics Department Colloquium
- Impact!
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee and cookies at 3:30 pm)
- Speaker: Sid Nagel, University of Chicago
- Abstract: When a liquid drop or a fluid stream hits a solid target it catastrophically deforms its shape in ways that can strongly violate our intuition. I will discuss two examples that raise issues about how a liquid interacts with itself and with its surroundings upon impact. The first experiment concerns an ordinary drop hitting a smooth dry surface. In this case the drop can create a splash in which a corona forms and breaks up into many small droplets. The second experiment deals with a granular stream hitting a target. In this situation, the material acts like a liquid with zero surface tension and has implications for how scattering takes place even at the submicroscopic level in studies of the quark-gluon plasma. A comparison of the granular jet with the heavy ion collisions raises questions about what it means to be a liquid.
- Host: Coppersmith