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Events During the Week of October 18th through October 25th, 2015

Monday, October 19th, 2015

Plasma Physics (Physics/ECE/NE 922) Seminar
The JET-ILW Pedestal and the Fate of the H-mode
Time: 12:00 pm
Place: 2241 Physics Bldg
Speaker: David Hatch, Institute for Fusion Studies, UT Austin,
Abstract: The tokamak H-mode is defined by a narrow insulating region—the pedestal—at the plasma edge where turbulence is suppressed and sharp pressure gradients develop. The properties of the pedestal largely determine the quality of confinement and are also closely connected to issues of heat exhaust and plasma material interaction. The pedestal is, therefore, at the center of the most pressing issues facing fusion energy. I will describe recent progress in understanding the dynamics of turbulence and transport in the singularly ITER-relevant JET-ILW (ITER-like wall) pedestal, where unexpected pedestal properties are responsible for a significant degradation in performance. Gyrokinetic simulations using the GENE code identify the microtearing mode to be the dominant transport mechanism in the pedestal. Nonlinear simulations demonstrate the capacity of microtearing turbulence to account for the observed experimental heat fluxes. The capabilities and insights developed in this work are used to infer possible consequences for pedestal properties on ITER, including the possibility that ITER may be in a pedestal regime foreign to present-day experiments.
Host: UW
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Tuesday, October 20th, 2015

Chaos & Complex Systems Seminar
What climate change and world change really mean for all of us
Time: 12:05 pm
Place: 4274 Chamberlin (refreshments will be served)
Speaker: Bernard Z. Friedlander, Department of Psychology, Emeritus, University of Hartford
Abstract: Can American and World politicians face the possibilities that some of our smartest scientists may be right about Climate Change? That’s what this presentation seeks to understand and explain: the standoff between– Authoritative assessments from massive bodies of data that forecast high probabilities of many widespread catastrophes; and Persistent struggles among some of our most powerful political and economic leaders to preserve business as usual. CCSS concepts of simplicity, intricacy, complexity and chaos appear to account for problems that must be overcome if America and the World can solve these problems before it’s too late.
Host: Sprott
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Theory Seminar (High Energy/Cosmology)
Galilean creation of the inflationary universe
Time: 3:30 pm
Place: 5280 Chamberlin Hall
Speaker: Masahide Yamaguchi, Tokyo Institute of Technology
Abstract: It has been pointed out that the null energy condition can be violated stably in some non-canonical scalar-field theories. This allows us to consider the Galilean Genesis scenario in which the universe starts expanding from Minkowski spacetime and hence is free from the initial singularity. We use this scenario to study the early-time completion of inflation, pushing forward the recent idea of Pirtskhalava et al. We present a generic form of the Lagrangian governing the background and perturbation dynamics in the Genesis phase, the subsequent inflationary phase, and the graceful exit from inflation, as opposed to employing the effective field theory approach. Our Lagrangian belongs to a more general class of scalar-tensor theories than the Horndeski theory and Gleyzes-Langlois-Piazza-Vernizzi generalization, but still has the same number of the propagating degrees of freedom, and thus can avoid Ostrogradski instabilities. We investigate the generation and evolution of primordial perturbations in this scenario and show that one can indeed construct a stable model of inflation preceded by (generalized) Galilean Genesis.
Host: Amol Upadhye
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Wednesday, October 21st, 2015

No events scheduled

Thursday, October 22nd, 2015

R. G. Herb Condensed Matter Seminar
Programmable nonreciprocity in multi-mode parametric devices
Time: 10:00 am
Place: 5310 Chamberlin Hall
Speaker: Dr. Leonardo Ranzani, BBN/Raytheon
Josephson Parametric Amplifiers (JPAs) can perform quantum-limited
readout of superconducting qubits. However, since they are
reflection-based amplifiers, an external RF circulator is always
necessary to suppress back-action. A new approach is to use directional
parametric amplification by driving multiple parametric processes
simultaneously with different pump phases. SQUID and SLUG amplifiers in
fact operate by a similar mechanism: the interference between parametric
processes driven by internal oscillations at the Josephson frequency
suppresses the reverse gain and explains the high level of isolation in
this devices. In this talk I am going to discuss a general approach to
the study of parametric devices driven by multiple pump signals. As
opposed to traditional JPAs, where only two modes, signal and idler,
interact, in multi-pump devices three or more modes are pumped
simultaneously. I will show how to use directed graphs to compute the
scattering properties of such multi-mode devices and design parametric
nonreciprocal components, including circulators and directional amplifiers.
Host: McDermott
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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:
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 Amol Upadhye (
Host: Amol Upadhye
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Astronomy Colloquium
Bautz Lecturer
"Exoplanetary Science's Kepler Revolution"
Time: 3:45 pm
Place: 4421 Sterling hall, Coffee and Cookies at 3:30 PM
Speaker: Professor John Johnson , Harvard CfA
Abstract: Just four years ago the prospect of finding rocky planets around other stars was still the subject of science fiction—none had been found and reasonable estimates put us decades away from such momentous discoveries. All of that has changed very recently on the heels of the extraordinarily successful NASA Kepler mission. I will provide an overview of Kepler science and the new view it has provided us on the demographics of exoplanets throughout the Galaxy. In addition to the statistics of exoplanets, I will also show highlights from the many unusual individual discoveries that have expanded our understanding of planet formation and allowed us to view our Solar System within a much broader context than ever before, including: Hundreds of new planets from the extended Kepler K2 Mission, a disintegrating planetesimal orbiting a white dwarf, and updates on the number of (and nearest) Earth-like, habitable zone planets in the Galaxy.
Host: Eric Wilcots
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Friday, October 23rd, 2015

Special Friday Noon Talk
"Where are all the black folk in astronomy?"
Time: 12:00 pm
Place: 4421 Sterling Hall
Speaker: Professor John Johnson , Harvard CfA
Abstract: Decades of diversity programs in STEM have had little to no impact on the racial demographics of astronomy and physics. Today, astronomy departments take an average of 30 years to graduate a Black or Latino PhD student, and the average PhD rate is 0.5 per year. The astronomy professoriate is only 1% Black, 1% Latino and 0% Native. I argue that aiming at diversity is the wrong approach. In order to explore better strategies, I will lead an interactive discussion with the audience, starting with the definition of four seemingly simple words. With the proper vocabulary in hand, I will provide a brief history of race in America that has led to the peculiar present-day racial makeup of our field.<br><br>
Host: Professor Eric Wilcots
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Physics Department Colloquium
Just Because We're Smart Doesn't Mean We're Crazy and Evil: Giving Scientists and Mathematicians a Fair Shake in Literary Fiction
Time: 3:30 pm
Place: 2241 Chamberlin Hall (Coffee & Cookies at 3:15pm)
Speaker: Stuart Rojstaczer, Writer/UW-Madison Alumni
Abstract: How scientists are characterized in popular culture and the arts likely plays a role in how much impact their opinions and research results have upon society. I am well aware, given my lengthy history as a research scientist, that much good science gets willfully ignored and dismissed in the political arena and by the public partly because they have a negative view of scientists that comes from popular culture. As a writer of literary fiction, I feel a political obligation to portray scientists and their work with realistic depth. How does one get past the societal cliché of scientists and mathematicians being socially withdrawn, eccentric, emotionally stunted and ultimately less than human? One approach is to ignore this cliché entirely and to portray them as, more or less, ordinary people who happen to work as scientists and mathematicians. Another approach is to embrace the cliché initially in order to attract an audience and then to subvert it. This latter approach is the one I prefer and employed in my latest novel, The Mathematician’s Shiva.
Host: Marshall Onellion
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