Events at Physics
Events During the Week of December 8th through December 15th, 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:
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 (email@example.com)
- Host: Peter Timbie
- Condensed Matter Theory Group Seminar
- Interplay between many-body and single-particle interactions in iridates and rhodates
- Time: 4:30 pm
- Place: Chamberin 5310
- Speaker: Yuriy Sizyuk, Physics Department
- Host: Natalia Perkins
- Chaos & Complex Systems Seminar
- Responding to climate change: poetry and local action
- Time: 12:05 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Robin Chapman and Jean Bahr, UW Department of Communicative Disorders and Department of Geoscience
- Abstract: What can individuals do? Robin Chapman reads from her new book of poems, One Hundred White Pelicans, work that arose from the Chaos and Complex Systems Seminars on climate change; and Jean Bahr talks about local action, including reroofing her house with solar shingles: they engage the questions of causal contributions to change, now and in the past; why it should matter to us now; and what we can do about it. Students and investigators in the field are especially welcome to contribute to discussion.
- Host: Clint Sprott
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
- R. G. Herb Condensed Matter Seminar
- Topological Kondo Insulators
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Victor Galitski, University of Maryland
- Abstract: In this talk I will review recent theoretical work on a new class of topological material systems - topological Kondo insulators, which appear as a result of interplay between strong correlations and spin-orbit interactions. I will start with introducing the by now standard theory of topological band insulators and explain the Fu-Kane method to calculate the Z2 topological index for time-reversal-invariant band structures in three dimensions. The method will be used to show that hybridization between the conduction electrons and localized f-electrons in certain heavy fermion compounds gives rise to interaction-induced topological insulating behavior. A mean field theory of these Kondo topological insulators will be derived. I will also discuss recent experimental results, which have conclusively confirmed our predictions in the Samarium hexaboride compound, where the long-standing puzzle of the residual low-temperature conductivity has been shown to originate from topological surface states. This material system represents the first true topological insulator observed experimentally with low-temperature transport dominated by the surface and essentially no conduction in the bulk. In conclusion, I will mention our ongoing theory work, which focuses on very unusual non-linear transport properties of Samarium hexaboride devices, which mimic neuron-like behavior in biological systems.
- Host: Vavilov
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Newborn Pulsars as sources of Ultrahigh Energy Cosmic Rays
- Time: 2:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Ke Fang, U. Chicago
- Abstract: The workings of the most energetic astrophysical accelerators in the Universe are encoded in the origin of ultrahigh energy cosmic rays (UHECRs). Current observations by the Auger Observatory, the largest UHECR observatory, show a spectrum that agrees with an extragalactic origin, as well as an interesting transition in chemical composition from light element to heavier element as energy increases. Candidate sources range from young neutron stars to gamma-ray bursts and events in active galaxies. In this talk, we will discuss newborn pulsars as the sources of ultrahigh energy cosmic rays. We will show that a newborn pulsar model naturally injects heavier elements and can fit the observed spectrum once propagation in the supernova remnant is taken into account. With the proper injection abundances, integrated cosmic rays from the extragalactic pulsar population can match observation in all aspects - energy spectrum, chemical composition, and anisotropy. We will also examine the fingerprints of their Galactic counterparts on cosmic ray spectrum . Lastly, we will discuss the multi-messenger smoking gun of this scenario - the detectability of high energy neutrinos from pulsars and magnetars.
- Host: Albrecht Karle
- Theory Seminar (High Energy/Cosmology)
- Strongly-Interacting Supersymmetry: Theoretical Motivations and Phenomenology
- Time: 12:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Lauren Pearce, UCLA
- Abstract: Current evidence from the LHC has pushed us to consider novel implementations of supersymmetry. One possibility is strongly-interacting supersymmetry, in which the trilinear couplings between the Higgs bosons and squarks are large; in such models, the squarks form bound states. In this talk, I will discuss theoretical motivations for such models (for example, that supersymmetry breaking can trigger electroweak symmetry breaking) and phenomenological concerns, including the possibility of electroweak baryogenesis and signals for ongoing LHC searches.
- Physics Department Colloquium
- Holiday Office Party
- Holiday Colloquium
- Time: 4:30 pm
- Place: 2103 Chamberlin Hall
- Speaker: 3rd Year Graduate Students, UW Madison
- Abstract: The third year class invites you to come and enjoy a catered, afternoon luncheon celebrating the holiday season. There will be fine Italian delicacies including fancy charcuterie, cave-aged cheeses, and local organic vegetables such as vine-ripened heirloom tomatoes. Beverages include the Midwest's world renowned heritage adult beverages and various artisanal carbonated liquids. Please enjoy these Yuletide festivities with a measure of cheer known only once a year in Chamberlin hall. Entertainment will be provided by the third year class.
Beer and Pizza will begin at 4:00 pm
Colloquium will begin at 4:30 pm
Participants must have a wristband to attend. Wristbands will be distributed Friday afternoon.
- Host: Department of Physics