Events at Physics |
Events During the Week of December 6th through December 13th, 2009
Monday, December 7th, 2009
- Plasma Physics (Physics/ECE/NE 922) Seminar
- High-Power Laser Experiments at the Large Plasma Device
- Time: 12:05 pm
- Place: 2301 Sterling
- Speaker: Chris Niemann, University of California/Los Angeles
Tuesday, December 8th, 2009
- Chaos & Complex Systems Seminar
- Living the unknown: A dancer's perspective
- Time: 12:05 pm
- Place: 5310 Chamberlin (Refreshments will be served)
- Speaker: Choi Myo-Young, UW Department of Dance
- Abstract: In these times of economic chaos, social turmoil, we live with a sense of growing insecurity about the future. Through the lens of dance, we can look to the past--both mythic and real--as a means to fearlessly face our future.
- Astronomy Colloquium
- The Ins and Outs of Stellar Oscillations
- Time: 3:30 pm - 5:00 pm
- Place: 3425 Sterling Hall
- Speaker: Richard Townsend, UW Astronomy Dept
- Abstract: Once thought to be a peculiarity exhibited by a minority of stars, stellar oscillations are now regarded as the rule rather than the exception. Across the whole Hertzsprung-Russell diagram, we see evidence of the periodic photospheric motions that are the hallmark of the excitation of one or more oscillation modes. In this review talk, I'll discuss the wave properties of these modes; explore the various mechanisms for their excitation; explain how they can be used to probe the internal structure of stars, through the discipline of asteroseismology; and, consider how oscillation modes might alter this internal structure.
- String Theory Seminar
- String Universality in Six Dimensions
- Time: 4:00 pm
- Place: 2301 Sterling Hall
- Speaker: Vijay Kumar, MIT
- Host: Gary Shiu
Wednesday, December 9th, 2009
- No events scheduled
Thursday, December 10th, 2009
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Dark Energy and Dark Matter from Gravitational Symmetry Breaking
- Time: 4:00 pm
- Place: 5310 Chamberlin
- Speaker: Andre Fuzfa, GAMASCO, University of Namur (FUNDP) and LUTH, Observatory of Paris.
- Abstract: Coupling dark matter (DM) to dark energy (DE) is one of the most promising way to build a unified description of the invisible sector of cosmology. However, such DM-DE couplings make the mass of the DM particles varying, therefore breaking the universality of free fall (Galileo's equivalence principle). Doing so, the strong equivalence principle, stating the universality of gravitational binding energy, does not hold anymore, particularly where DM is profuse like in the large-scale universe. Such mass-varying DM particles therefore constitute an Abnormally Weighting type of Energy (AWE Hypothesis) and their cosmological abundance induces modifications of gravity on large-scales, modifications that can explain cosmic acceleration. I will present here how this AWE hypothesis can be naturally achieved in terms of the explicit symmetry breaking of a global U(1) symmetry in particle physics. In this context, the U(1)-charged complex scalar usually splits into a mass-varying pseudo-Nambu-Goldstone boson (axion-like DM particles) while the vacuum expectation value of the complex scalar has to be stabilised, usually through the use of the potential (spontaneous symmetry breaking mechanism). We show here that the cosmological relaxation toward the equivalence principle can play this crucial stabilising role and explain in addition the observed cosmic acceleration. Stabilisation of the new scalar is achieved through non-minimal gravitational couplings. We will show several remarkable cosmological predictions of this idea and emphasize some interesting applications on neutrino physics for the gravitational symmetry breaking of lepton number symmetry.
- Host: Sonny Mantry
Friday, December 11th, 2009
- Physics Department Colloquium
- Holliday Colloquium--Evidence for Colloquium Posters Having Nothing to do with Colloquium
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall
- Speaker: Holliday Colloquium
- Abstract: The colloquium poster (P^c) has been found in deep inelastic scattering experiments to consist of a title, an abstract, and a figure which either attempts humor or appears to contain all knowledge. We present evidence that the poster is a kind of trap, in which the interesting-sounding poster describing applications to all of physics instead yields to a monotone delivery of a highly technical talk on computation of 3rd-order Albatross diagrams. This has clear implications for condensed matter and atomic physics, the origin of ultra high-energy cosmic rays, electroweak symmetry breaking, and plasma containment (see figure).
- Host: Grad Students