Events at Physics
Events During the Week of November 5th through November 11th, 2017
- Plasma Physics (Physics/ECE/NE 922) Seminar
- A General Framework to Analyzing Multi-Scale Complex Flows: Applications to Oceanic, Plasma, and Compressible Flows
- Time: 12:00 pm
- Place: Chamberlin 2241
- Speaker: Prof. Hussein Aluie, University of Rochester
- Abstract: Flows in nature and in engineering are often complex, forced by external agents, boundary stresses, and internal instabilities, and pervaded by multiscale structures such as eddies, plumes, jets, waves, and turbulence --spanning many orders of magnitude in size. The nonlinear nature of the dynamics implies a coupling between these multiple scales, which often plays a major role in determining mean-flow evolution and is a primary factor limiting our predictive modeling capabilities. To tackle this class of problems in fluid dynamics, I will present a scale-analysis framework we have been developing that is rooted in commonly used techniques in the subjects of PDEs and Large Eddy Simulation modeling (LES). The approach is very general and allows for resolving nonlinear processes at any scale and at any location in the flow. It relies on a synergistic interplay between rigorous mathematics, physical insight, and numerical computations to probe large data sets from simulations, satellite observations, and experimental measurements. I will discuss the application of this methodology to oceanic, plasma, and compressible flows.
- Host: Stanislav Boldyrev
- Chaos & Complex Systems Seminar
- Multidimensional spectroscopy of complex chemical systems: Using nonlinearity to isolate signals
- Time: 12:05 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Blaise Thompson, UW Department of Chemistry
- Abstract: Chemical systems are typically composed of many individual components. Each component may be unique. Furthermore, each component may experience a different chemical environment. At room temperature, these environments evolve on ultrafast time scales. Scientists need specialized techniques to understand what is happening in these complex, coupled systems.
Spectroscopy uses the interaction of light and matter to measure chemical energies. Multidimensional spectroscopy (MDS) capitalizes on nonlinearities in this interaction to peer into higher-order properties of the chemical system. These higher-order signals reveal coupling parameters of the system. In this way, scientists can use MDS to isolate unique properties of chemical systems that cannot be measured through other means. Ultrafast dynamics can also be tracked.
This presentation will introduce the basic concepts of MDS. An intuitive description of the technique will be presented. Practical advantages will be highlighted.
- Host: Clint Sprott
- No events scheduled
- R. G. Herb Condensed Matter Seminar
- Enhancing cavity QED via anti-squeezing: synthetic ultra-strong coupling and entangled cat-states
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Dr. Luke Govia, University of Chicago
- Abstract: We present applications of parametric (two-photon) driving of a cavity in a generic cavity QED setup, which can be used to exponentially enhance the light-matter coupling. This can take a weakly coupled system into the strong coupling regime (where the coupling exceeds dissipative rates) and even the ultra-strong coupling regime (where the coupling is comparable to the cavity frequency). As an example, we show how this allows one to use a weak-coupling system to adiabatically prepare the highly entangled ground state of the ultra-strong coupling system. Furthermore, we show that by adding local Kerr nonlinearities to parametrically driven cavities one can stabilize an entangled cat-state between the cavities.
- Host: McDermott
- Astronomy Colloquium
- "Simulations of Black hole Accretion and Outflows"
- Time: 3:30 pm
- Place: 4421 Stering Hall, Coffee and cookies 3:30 pm, Talk begins at 3:45 pm
- Speaker: Alexander Tchekhocvskoy, Northwestern University
Black holes are responsible for a wide variety of astrophysical phenomena. They devour stars, eject relativistic jets, affect star formation and galaxy evolution, and enrich the Universe with heavy elements. I will discuss how global general relativistic magnetized fluid dynamics numerical simulations allow us to use this activity to quantitatively probe strong-field gravity and constrain black hole physics in various astrophysical context
- Graduate Introductory Seminar
- WIPAC: IceCube, HAWC, CTA, ARA
- Time: 12:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Halzen, Hanson, Karle, Vandenbroucke, Westerhoff
- Physics Department Colloquium
- Neutrino Oscillations - A Door to New Physics
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Brian Rebel, Fermi Lab
- Abstract: One of the biggest surprises in Particle Physics was the discovery of neutrino mass - a result that proves the Standard Model governing Particle Physics is incomplete! This fundamental property of neutrinos was discovered through neutrino oscillations, or changing of neutrino flavor, between the points of neutrino production and interaction. For example, about two thirds of the electron neutrinos produced in solar fusion reactions have been shown to change into a mixture of muon and tau neutrinos as they propagate out of the Sun. Similarly, about half the muon neutrinos produced from cosmic ray interactions in the atmosphere change into tau neutrinos. These neutrino oscillations allow us to make precision measurements of neutrino properties using man-made sources such as neutrino beams and nuclear reactors.
In this talk I will present the current understanding of neutrino oscillations and the outstanding questions about neutrinos. I will present the current results from the NOvA experiment, which uses the most powerful accelerator neutrino beam in the world, and a look to the future with the DUNE experiment and the exciting new detector technology it uses.
- Host: Sridhara Dasu
- Graduate School Admissions Q&A II: Graduate Student Panel
- Time: 5:00 pm
- Place: 2223 Chamberlin
- Abstract: Anyone interested in learning more about graduate school is welcome to attend a Q&A panel of graduate students ready to answer questions on what it’s like being in grad school, tips for applying, getting involved in research, and overall information and advice.