Events at Physics |
Events During the Week of December 7th through December 14th, 2014
Monday, December 8th, 2014
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Relativistic runaway electrons
- Time: 12:00 pm - 1:00 pm
- Place: 2535 Engineering Hall
- Speaker: Boris Breizman, The University of Texas at Austin
- Host: CPTC
- Cosmology Journal Club
- An Informal discussion about a broad variety of arXiv papers related to Cosmology
- Time: 12:15 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
- Council Meeting
- Time: 4:00 pm
- Place: 2314 Chamberlin (Chair's Conference Room)
Tuesday, December 9th, 2014
- Chaos & Complex Systems Seminar
- Chasing fast dynamos in the Plasma Lab
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Cary Forest, UW Department of Physics
- Abstract: The Madison Plasma Dynamo eXperiment is now exploring a hitherto unexplored part of parameter space where dynamos operate in nature. Dynamos are systems which continuously transform kinetic energy from plasma flow into magnetic energy. Discovering the conditions under which dynamos self-generate magnetic fields and then understanding how this field changes plasma dynamics is one of the most compelling questions in all of plasma astrophysics. In plasma astrophysics, the most important issue to be resolved is the fast large scale dynamo problem, namely "How does a highly conducting turbulent plasma self-generate magnetic energy at small-scales that ultimately self-organizes into large scale field?" MPDX has the potential to study dynamos, including fast dynamos, and related processes experimentally. I'll explain what this is and how we can make this happen in my talk.
- Host: Clint Sprott
- Theory Seminar (High Energy/Cosmology)
- Boosting Dark Matter Indirect Detection Signals with Black Holes
- Time: 3:00 pm - 4:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Jessie Shelton
- Abstract: Super-massive black holes that grow at the center of dark matter halos distort the dark matter within their zone of influence into a steep density spike. Besides giving rise to strong enhancements of standard indirect detection signals, this spike can lead to qualitatively new windows into the physics of the early universe. I will talk about potential dark matter signals from the Milky Way's central black hole, some astrophysical caveats, and the possible use of black holes as dark matter accelerators.
- Host: Ran Lu
- Faculty Search Committee Meeting
- Faculty Search Committee Meeting (Particle)
- Time: 4:00 pm - 5:00 pm
- Place: 4272 Chamberlin Hall
- Host: Sridhara Dasu
Wednesday, December 10th, 2014
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
Thursday, December 11th, 2014
- R. G. Herb Condensed Matter Seminar
- Probing the Materials Origins of Decoherence in Superconducting Qubits
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Dr. Vincenzo Lordi, Lawrence Livermore Lab
- Abstract: The practicality of superconducting qubits for scalable quantum computing applications is limited by decoherence noise that reduces the useful lifetime of the quantum states. While various theories explain possible mechanisms for the decoherence, the microscopic origins at the level of the materials comprising actual devices remain largely unknown. Such knowledge is essential to enabling rational improvement of fabrication processes for higher performing qubits. First-principles simulations at the atomic level provide a useful tool to probe the materials origins of decoherence. Here, we discuss recent work investigating magnetic fluctuators associated with materials defects that can contribute decoherence noise in these systems. In particular, native defects and adsorbates on the surface of sapphire and dangling bond defects on the surface of amorphous silica will be discussed. In addition, interactions among spins on surfaces can be important, and we present detailed calculations on the energetics of such interactions. We find that the spin-spin coupling strength can be strongly influenced by lattice strain and the presence of defects. Finally, an analysis of the correlations between local structural and electronic properties of amorphous materials will be presented in this context.
- Host: McDermott
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- A preview of the Planck 2014 cosmology
- Time: 2:30 pm - 3:30 pm
- Place: 4272 Chamberlin Hall
- Speaker: Ben Wandelt, Institut Astrophysique de Paris
- Abstract:
The cosmic microwave background (CMB) carries a cosmic message, preserved through time, written in its anisotropies. The Planck mission is now about to reveal a new chapter of this message using high-resolution nearly all-sky information of the polarization anisotropies for the first time, in addition to upgrading from the nominal mission to the full mission data set. These data provide new insights into several open questions related to the nature of the primordial fluctuations that seeded all structure; the global properties of the universe; neutrinos; dark matter; dark energy; atomic physics; and gravity. - Host: Peter Timbie
- Astronomy Colloquium
- The Cosmological Context of Star Formation
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall
- Speaker: Tom Quinn, University of Washington
- Abstract: On the molecular cloud scale, star formation is a very complicated
process that involves gravitational collapse, radiative transfer and magnetic fields on sub-parsec scales. On the other hand, there are a number of observed relationships between star formation and galactic and cosmic environment such as star formation rate - molecular surface density relationship in disk galaxies, the stellar mass - halo mass relationship, and the evolution of the star formation rate over time.
Modeling these relationships therefore requires simulations of
enormous dynamic range and well motivated prescriptions for the star formation physics that is still unresolved. Here, I will describe techniques for capturing this dynamic range, and models for star formation and its interaction with the interstellar medium. I will also describe recent successes in understanding star formation histories as function galactic size, merger history and cosmic time.
Friday, December 12th, 2014
- R. G. Herb Condensed Matter Seminar
- Strong, Engineered Photon/Spin Qubit Coupling
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Alex Rimberg, Dartmouth
- Abstract: Spin qubits, due to their long coherence times, offer great promise for use in quantum computation. At the same time, rapidly manipulating, reading out, and coupling such qubits over long distances remain experimental challenges. In this talk I will discuss a scheme that uses a Cooper pair transistor to induce a strong, engineerable coupling between a spin qubit and photons in a superconducting microwave cavity. This scheme offers the potential to both read out and manipulate a spin qubit using only one to a few cavity photons.
- Host: Eriksson
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Variability of TeV gamma-ray blazars
- Time: 2:00 pm - 3:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Qi Feng, Purdue University
- Abstract: Blazars belong to a subclass of radio loud AGN with a relativistic jet closely aligned to our line of sight. They are characterized by highly variable non-thermal emission at almost all wavelengths. Similar to gamma-ray bursts, the studies of gamma-ray variability can shed light on gamma-ray emitting regions and production mechanisms in blazars in a relatively model-independent way. With its superior sensitivity, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) provides us with an opportunity to study rapidly variable gamma-ray emission at TeV energies. In this talk, I will describe the VERITAS experiment and show some recent results from our studies of blazar variability that are based primarily on the VERITAS observations but are interpreted in a multi-wavelength context.
- Host: Vandenbroucke
- Physics Department Colloquium
- Holiday Colloquium -- A Treatise on the Probabalistic Projectile PizZA Problem
- Time: 4:00 pm - 12:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: University of Wisconsin, Madison
- Abstract: Patrons of past PizZA participatory parties have made note of a seemingly unphysical amount of sustenance stretched over the multidimensional space-time locale traditionally repeatably referred to as “Holiday Colloquium.” The University of Wisconsin - Madison’s crack-squad of upper-management business brilliants have researched how other institutions manage to acquire the nutritional supplement PizZA in greater quantities and have found an elegant and simple response function. In this talk, a compactified solution to the PizZA problem is presented at first very simply with assistance from the higher-order pile-up theories of Ian and Domino resulting in a final filling factor increase of order 50%.
Pizza at 4:00pm
Show at 4:30pm
- Host: 3rd Year Graduate Students