Events at Physics |
Events on Tuesday, September 10th, 2013
- Chaos & Complex Systems Seminar
- Multistability and hidden attractors
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Clint Sprott, UW Department of Physics
- Abstract: One characteristic of nonlinear dynamical systems is that they can have more than one stable equilibrium. Perturbations of the variables or changes in the parameters can cause the system to abruptly switch from one equilibrium to the other from which it is hard to recover (what Al Gore calls a "tipping point"). Furthermore, equilibria can become unstable and give birth to periodic oscillations and even chaos. Hence, in addition to static attractors, there can be limit cycles and strange attractors, and several such attractors can coexist in even simple systems. Sometimes these attractors are "hidden" in the sense that they cannot be found by starting from the vicinity of an unstable equilibrium. Such hidden attractors can be catastrophic if the system is a building, a bridge, or an airplane wing. Examples of such behavior will be illustrated in very simple systems of differential equations and with simple demonstrations.
- Host: Clint Sprott
- Atomic Physics Seminar
- Atomic clocks, fundamental symmetries, and the search for new physics
- Time: 2:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Marianna Safronova, University of Delaware
- Abstract: I will give an overview of searches for new physics with atomic systems, including the study of parity violation, search for EDM, and the search for variation of fundamental constants. The study of parity nonconservation in cesium led to a first measurement of the nuclear anapole moment and allowed to place constraints on weak meson-nucleon couplings. I will review the present status of atomic parity violation studies and the implications for searches for physics beyond the standard model and study of weak hadronic interactions. In the second part of my talk, I will discuss the state-of-the art atomic clock development focusing on the issue of the blackbody radiation shifts as well as application of clocks to the searches for variation of the fine-structure constant.
- Host: Saffman