Events at Physics |
Events During the Week of November 3rd through November 9th, 2013
Monday, November 4th, 2013
- Cosmology Journal Club
- An Informal discussion about a broad variety of arXiv papers related to Cosmology
- Time: 12:30 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
http://cmb.physics.wisc.edu/journal/index.html
Please feel free to bring your lunch!
If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Le Zhang (lzhang263@wisc.edu) - Host: Peter Timbie
- Condensed Matter Theory Group Seminar
- Full Counting Statistics of Photons Emitted by Double Quantum Dot
- Time: 4:30 pm
- Place: Chamberin 5310
- Speaker: Canran Xu, Physics Department
- Abstract: We analyze the full counting statistics of photons emitted by a double quantum dot (DQD) coupled to a high-quality microwave resonator by electric dipole interaction. We show that at the resonant condition between the energy splitting of the DQD and the photon energy in the resonator, photon statistics exhibits both a sub-Poissonian distribution and antibunching. In the ideal case, when the system decoherence stems only from photodetection, the photon noise is reduced below one-half of the noise for the Poisson distribution and is consistent with current noise. The photon distribution remains sub-Poissonian even at moderate decoherence in the DQD. We demonstrate that Josephson junction based photomultipliers can be used to experimentally assess statistics of emitted photons.
- Host: Natalia Perkins
Tuesday, November 5th, 2013
- Chaos & Complex Systems Seminar
- Optimizing the design of air pollution control measures to improve human health
- Time: 12:05 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Jamie Schauer, UW Department of Civil and Environmental Engineering
- Abstract: Hundreds of studies have clearly demonstrated that higher levels of air pollution are associated with increases in adverse health effects in human populations. The adverse health effects associated with air pollution exposure include mortality and morbidity that are linked to respiratory disease, cardiovascular disease, and reproductive complications. As one of the largest environmental risk factors, the economic costs or air pollution have been estimated to be over one trillion dollars per year in the USA alone. However, the costs associated with mitigation of air pollution are not trivial and policies for air pollution mitigation often face political and social barriers. As more effective and efficient control strategies are sought to reduce the impacts of air pollution, a robust understanding of how reduction in the emissions from specific sources will change the composition of air pollution and reduce the adverse impacts of air pollution. Given the complexity of air pollution sources, air pollution transport and transformations, and the biological pathways of disease associated with air pollution exposure; quantifying these relationships require an understanding of a number of very complex and integrated systems. These systems include: 1) the design and operations of mobile sources of air pollution, stationary power generation, residential air pollution sources, and industrial emissions of air pollution; 2) the physical and chemical processes of impacting the transport and transformations of pollutants in the atmosphere; 3) the behavioral activities of people that lead to exposures of air pollution, 4) the biological susceptibility of the exposure populations, and 5) the pathways of disease associated with exposure to air pollution. This seminar will provide background about these systems important to understand the health effects of air pollution, as well as research methods that are being used to bridge across the highly diverse domains.
Wednesday, November 6th, 2013
- Physics Club Event
- Graduate Student Panel
- Time: 5:30 pm
- Place: 4274 Chamberlin
- Abstract: Come hear UW-Madison graduate students in physics, astronomy, mathematics, medical physics, and science education discuss their experiences leading up to graduate school and their experiences in graduate school. Food will be provided.
- Host: Physics Club
Thursday, November 7th, 2013
- R. G. Herb Condensed Matter Seminar
- Ultracold atoms in synthetic gauge fields: Novel phases and dynamics
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Arun Paramekanti, University of Toronto
- Abstract: Experimental developments in the field of ultracold atomic gases
have enabled the creation of artificial Lorentz forces and spin-orbit coupling. The combination of such "synthetic gauge fields" and strong correlations in an optical lattice is shown
to lead to novel phases including Mott insulators which support loop current orders and magnetic skyrmion crystals. These bosonic chiral Mott insulators are analogous to vector chiral phases of frustrated magnets. We show that studying quantum quench
dynamics yields a particularly transparent route to imaging such current orders, enabling the detection of bulk equilibrium currents as well as topological chiral edge currents. Similar
ideas are also shown to be applicable to orbital states of such ultracold atoms, leading to chiral orbital Bose liquid states. Such complex orbital order can be uncovered using quenches
which lead to orbital dynamics, analogous to NMR pulse experiments that probe spin dynamics.
- Astronomy Colloquium
- Massive Star Formation Through the Universe
- Time: 3:30 pm
- Place: 4421 Sterling Hall
- Speaker: Jonathan Tan, University of Florida
- Abstract: Massive stars have played a dominant role in shaping our universe since its earliest times, but there is no consensus on the mechanism by which they form. I review the physical processes thought to be important in massive star formation, concentrating on a particular theoretical model, Turbulent Core Accretion. This assumes the initial conditions are massive, turbulent, magnetized cloud cores of gas and dust that are reasonably close to virial equilibrium. We test this via theoretical simulations of the physics and chemistry of the interstellar medium and observational searches for these cores. We next consider the protostellar collapse phase as a massive star grows from the core. Various forms of feedback become important in reducing the efficiency of accretion, although it is not clear if one particular mechanism operates to set a fundamental limit on the maximum stellar mass. Again, these theoretical ideas can be tested by observations of massive stars forming in our Galaxy today. Finally, I discuss an application of massive star formation theory to the early universe: how massive were the first stars and could they have been the progenitors of supermassive black holes?
- Host: Audra Hernandez
Friday, November 8th, 2013
- Theory Seminar (High Energy/Cosmology)
- Title to be announced
- Time: 2:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Sam McDermott, University of Michigan
- Theory Seminar (High Energy/Cosmology)
- Constraining Dark Matter with Background Light
- Time: 2:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Sam McDermott, University of Michigan
- Abstract: Photons are generic in final states of dark matter annihilation or decay, and a wide range of X-ray and gamma ray observations are available to constrain broad classes of dark matter models. In the first part of the talk I will survey some robust bounds derived in the context of light decaying dark matter. These bounds are applicable in complete generality, making no assumptions about background models or underlying astrophysics, and they can be applied both in model dependent and model independent contexts. In the latter part of the talk, I will discuss some work in progress that focuses on bounds on annihilating dark matter from the isotropic gamma ray background.
- Physics Department Colloquium
- Higgs Boson Discovery: What's Next?
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall (coffee at 4:30 pm)
- Speaker: Marcela Carena, Fermilab & Kavli Institute for Cosmological Physics
- Abstract: The ATLAS and CMS experiments at the Large Hadron Collider at CERN have recently discovered a new particle, that has properties consistent with those of a Higgs boson associated with the mechanism that generates the mass of all the fundamental particles in nature. Such a discovery poses questions that may point towards new physics beyond the Standard Model of particle physics, and may shed light to some of the most fundamental questions of science: The unication of all the forces; the explanation of the matter-antimatter asymmetry of the universe; and the nature and origin of dark matter. I will discuss the interpretation of the latest experimental results relevant for Higgs physics both within the Standard Model and in its extension through an enhanced symmetry of nature, called "Supersymmetry".
- Host: Bai