Events at Physics |
Events During the Week of February 21st through February 28th, 2021
Monday, February 22nd, 2021
- Plasma Physics (Physics/ECE/NE 922) Seminar
- DIII-D and The Advanced Tokamak Path to Fusion Energy
- Time: 12:00 pm
- Place: Zoom
- Speaker: Richard Buttery, GA
- Abstract: The Advanced Tokamak represents a concept for fusion energy in which a magnetically confined plasma sustains itself in a stationary state. It is found that at high pressure, ion orbit affects can drive the necessary current in the plasma, while the fusion process keeps the plasma hot. Such pressures can be reached by shaping the plasma's physical geometry and current distribution to improve underlying stability and turbulent heat fluxes. The benefits of this more efficient approach is that it can reduce the current needed to be carried by the plasma, which greatly improves stability, heat and neutron fluxes. This talk will discuss the scientific principles behind the advanced tokamak approach to a fusion power plant, going on to present what such a device might look like and what research challenges it poses. We will then discuss these challenges and consider how DIII-D can address the critical plasma physics questions with research programs and new capabilities.
Chris Hegna is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
https://uwmadison.zoom.us/j/91835419103?pwd=YXhDdGlFeEZtc0c0MlZySUp0Q1FrUT09
Meeting ID: 918 3541 9103
Passcode: 578475
One tap mobile
+13126266799,,91835419103#,,,,*578475# US (Chicago)
+19292056099,,91835419103#,,,,*578475# US (New York)
Dial by your location
+1 312 626 6799 US (Chicago)
+1 929 205 6099 US (New York)
+1 301 715 8592 US (Washington D.C)
+1 346 248 7799 US (Houston)
+1 669 900 6833 US (San Jose)
+1 253 215 8782 US (Tacoma)
Meeting ID: 918 3541 9103
Passcode: 578475
Find your local number: https://uwmadison.zoom.us/u/aUzS5iS97
Join by SIP
91835419103@zoomcrc.com
Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia)
149.137.40.110 (Singapore)
64.211.144.160 (Brazil)
69.174.57.160 (Canada)
207.226.132.110 (Japan)
Meeting ID: 918 3541 9103
Passcode: 578475
- Host: Chris Hegna
- Plasma Theory Seminar
- Automated Normal Mode Analysis in Reduced Models of Turbulence for Stellarator Optimization
- Time: 4:00 pm
- Place: Zoom meeting
- Speaker: Ben Faber, UW-Madison
- Abstract: Chris Hegna is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
https://uwmadison.zoom.us/j/9548787359?pwd=VndwdGVMd2doQzVBWlgrZFc1Ni9pUT09
Meeting ID: 954 878 7359
Passcode: 4Ugg1v
Join by SIP
http://9548787359@zoomcrc.com
Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia)
149.137.40.110 (Singapore)
64.211.144.160 (Brazil)
69.174.57.160 (Canada)
207.226.132.110 (Japan)
Meeting ID: 954 878 7359
Passcode: 596249 - Host: Chris Hegna
Tuesday, February 23rd, 2021
- Council Meeting
- Physics Council
- Time: 4:00 pm
- Place: https://uwmadison.zoom.us/j/98476092525?pwd=Q3hBWmVZYkxOWUdBMmFpa2dKSFRIQT09
- Host: Sridhara Dasu
Wednesday, February 24th, 2021
- Plasma Theory Seminar
- Special Plasma Seminar
- Plasma rotation: from mass separation applications to light manipulation
- Time: 9:00 am
- Place: Zoom Meeting https://uwmadison.zoom.us/j/97739087835
- Speaker: Renaud Gueroult, Laplace, Université de Toulouse, CNRS, Toulouse, France
- Abstract: Rotation phenomena in plasmas are found everywhere, from plasma technologies to laboratory experiments and all the way to astrophysics, and can lead to peculiar effects. In this talk, I will first discuss how the mass differential confinement properties found in a rotating plasma could enable developing mass separation technologies [1] with high upside potential for societal applications including nuclear waste cleanup and rare earth recycling. I will then show how the problem of crossed-field rotation control is intimately tied to the question of what cross-field conductivity is in a rotating plasma, and how answering this basic question is also crucial to certain alternative magnetic confinement fusion concepts [2]. Finally, as a further illustration of the peculiar effects of rotation, I will briefly touch on the basic effect of rotation on wave polarization, and how this may be of importance for pulsars' physics [3] and light manipulation applications.
[1] Gueroult R., Rax J.-M., Zweben S. J. and Fisch, N. J., Plasma Phys. Control. Fusion, 2018, 60, 014018
[2] Rax J. M., Gueroult, R. and Fisch, N. J., Phys. Plasmas, 2017, 24, 032504
[3] Gueroult R., Shi Y., Rax J.-M. and Fisch N. J., Nat. Commun., 2019, 10, 3232
Cary Forest is inviting you to a scheduled Zoom meeting
Join Zoom Meeting
https://uwmadison.zoom.us/j/97739087835
Meeting ID: 977 3908 7835
One tap mobile
+13017158592,,97739087835# US (Washington DC)
+13126266799,,97739087835# US (Chicago)
Dial by your location
+1 301 715 8592 US (Washington DC)
+1 312 626 6799 US (Chicago)
+1 929 205 6099 US (New York)
+1 253 215 8782 US (Tacoma)
+1 346 248 7799 US (Houston)
+1 669 900 6833 US (San Jose)
Meeting ID: 977 3908 7835
Find your local number: https://uwmadison.zoom.us/u/amOIw9zUh
Join by SIP
97739087835@zoomcrc.com
Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia Sydney)
103.122.167.55 (Australia Melbourne)
149.137.40.110 (Singapore)
64.211.144.160 (Brazil)
69.174.57.160 (Canada Toronto)
65.39.152.160 (Canada Vancouver)
207.226.132.110 (Japan Tokyo)
149.137.24.110 (Japan Osaka)
Meeting ID: 977 3908 7835 - Host: Cary Forest
- Physics ∩ ML Seminar
- Neural Mechanics: Symmetry and Broken Conservation Laws in Deep Learning Dynamics
- Time: 11:00 am
- Place: Online Seminar: Please sign up for our mailing list at www.physicsmeetsml.org for zoom link
- Speaker: Daniel Kunin and Hidenori Tanaka, Stanford University
- Abstract: Understanding the dynamics of neural network parameters during training is one of the key challenges in building a theoretical foundation for deep learning. A central obstacle is that the motion of a network in high-dimensional parameter space undergoes discrete finite steps along complex stochastic gradients derived from real-world datasets. We circumvent this obstacle through a unifying theoretical framework based on intrinsic symmetries embedded in a network’s architecture that are present for any dataset. We show that any such symmetry imposes stringent geometric constraints on gradients and Hessians, leading to an associated conservation law in the continuous-time limit of stochastic gradient descent (SGD), akin to Noether’s theorem in physics. We further show that finite learning rates used in practice can actually break these symmetry induced conservation laws. We apply tools from finite difference methods to derive modified gradient flow, a differential equation that better approximates the numerical trajectory taken by SGD at finite learning rates. We combine modified gradient flow with our framework of symmetries to derive exact integral expressions for the dynamics of certain parameter combinations. We empirically validate our analytic expressions for learning dynamics on VGG-16 trained on Tiny ImageNet. Overall, by exploiting symmetry, our work demonstrates that we can analytically describe the learning dynamics of various parameter combinations at finite learning rates and batch sizes for state of the art architectures trained on any dataset.
- Host: Gary Shiu
- Department Meeting
- Time: 12:15 pm
- Place: Virtual see "abstract" for connection info
- Speaker: Sridhara Dasu, Department Chair
- AIMEE N LEFKOW is inviting you to a scheduled Zoom meeting.
Topic: Department Meeting
Time: Jan 13, 2021 12:15 PM Central Time (US and Canada)
Every week on Wed, until May 12, 2021, 18 occurrence(s)
Jan 13, 2021 12:15 PM
Jan 20, 2021 12:15 PM
Jan 27, 2021 12:15 PM
Feb 3, 2021 12:15 PM
Feb 10, 2021 12:15 PM
Feb 17, 2021 12:15 PM
Feb 24, 2021 12:15 PM
Mar 3, 2021 12:15 PM
Mar 10, 2021 12:15 PM
Mar 17, 2021 12:15 PM
Mar 24, 2021 12:15 PM
Mar 31, 2021 12:15 PM
Apr 7, 2021 12:15 PM
Apr 14, 2021 12:15 PM
Apr 21, 2021 12:15 PM
Apr 28, 2021 12:15 PM
May 5, 2021 12:15 PM
May 12, 2021 12:15 PM
Please download and import the following iCalendar (.ics) files to your calendar system.
Weekly: https://uwmadison.zoom.us/meeting/tJYpfuCrrD4vEtyo-iHQ60Kr6o_QGlZ3oBT4/ics?icsToken=98tyKuCqqjIjGdaQtRGPRowQBor4XenzpiVYj7dEk1LsKxEFMijkYO19A5VzKovf
Join Zoom Meeting
https://uwmadison.zoom.us/j/92499325588?pwd=T3lwZjEveWJqNGgrU3ljRmdTS0hOdz09
Meeting ID: 924 9932 5588
Passcode: 337209
One tap mobile
+19292056099,,92499325588#,,,,*337209# US (New York)
+13017158592,,92499325588#,,,,*337209# US (Washington D.C)
Dial by your location
+1 929 205 6099 US (New York)
+1 301 715 8592 US (Washington D.C)
+1 312 626 6799 US (Chicago)
+1 669 900 6833 US (San Jose)
+1 253 215 8782 US (Tacoma)
+1 346 248 7799 US (Houston)
Meeting ID: 924 9932 5588
Passcode: 337209
Find your local number: https://uwmadison.zoom.us/u/abhpt7GE9P
Join by SIP
92499325588@zoomcrc.com
Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia)
149.137.40.110 (Singapore)
64.211.144.160 (Brazil)
69.174.57.160 (Canada)
207.226.132.110 (Japan)
Meeting ID: 924 9932 5588
Passcode: 337209
- Host: Sridhara Dasu
Thursday, February 25th, 2021
- Cosmology Journal Club
- Time: 12:00 pm
- Place:
- Abstract: Cosmology Journal Club is back! We will be having virtual meetings this semester.
Each week, we start with a couple scheduled 15 minute talks about one's research, or an arXiv paper. The last 30 minutes will typically be open to the group for anyone to discuss an arXiv paper.
All are welcome and all fields of cosmology are appropriate.
Contact Ross Cawthon, cawthon@wisc, for more information.
Zoom info
Meeting ID: 93592708053, passcode: cmbadger
Or click:
https://uwmadison.zoom.us/j/93592708053?pwd=VWVNMDJXV2N1blV0emg4ZUg3ZGRiUT09 - Astronomy Colloquium
- PHANGS Results: Connecting the Small Scale ISM Physics to the Galaxy Structures
- Time: 3:30 pm
- Place: Zoom meeting(see Abstract ) Coffee and tea 3:30pm, Talk 3:45pm
- Speaker: Dyas Otomo, NRAO
- Abstract: The physical and dynamical states of molecular gas are closely tied to the location and amount of star formation in galaxies. This interaction between molecular gas and star formation occurs in small scale (< 100pc), therefore, high resolution observations are needed. PHANGS-ALMA mapped CO line emission in 90 nearby galaxies at 1’’ (~100 pc) resolution to quantify the physics of star formation and feedback at the scale of individual giant molecular clouds (GMCs) and connecting these
measurements to the galaxy-scale properties. In this talk, I will present recent results from the PHANGS collaboration. First, I will show that the molecular gas in roughly in viral equilibrium, but their properties vary between regions inside galaxies. Second, I will present recent measurement of the star formation efficiency per free fall time at the GMC scale. Third, I will explain how we can estimate the stellar feedback and GMCs lifetime though statistical analysis. Finally, I will conclude by showing that the star formation process is self regulated.
Zoom Link:
https://uwmadison.zoom.us/j/88513896776?pwd=Y1JtRE1KZllxWkFTamJBSGtGdm9yQT09
- Host: Professor Ellen Zweibel
Friday, February 26th, 2021
- Thesis Defense
- Thermal Transport Across Interfaces, Two-Dimensional Materials, and III-V Ternary-Alloy Superlattice
- Time: 12:00 pm
- Place: https://uwmadison.zoom.us/j/94109262267?pwd=Y0FrbklUdWRoa21weVp4dS83WjNvdz09
- Speaker: Gabriel Jaffe, Physics PhD Graduate Student
- Abstract: Time: Feb 26, 2021 12:00 PM Central Time (US and Canada)
Join Zoom Meeting
https://uwmadison.zoom.us/j/94109262267?pwd=Y0FrbklUdWRoa21weVp4dS83WjNvdz09
Meeting ID: 941 0926 2267
Passcode: 435668 - Host: Mark Eriksson, Faculty Advisor
- Theory Seminar (High Energy/Cosmology)
- Decoding and bootstrapping cosmological fluctuations
- Time: 2:00 pm
- Place: For zoom link, sign up at: https://groups.google.com/a/g-groups.wisc.edu/d/forum/theoryseminars/join
- Speaker: Guilherme Pimentel, Leiden University & University of Amsterdam
- Abstract: I will review our current understanding of the initial conditions of the universe, and describe what information is available from current and future measurements of cosmological correlation functions. Then I will describe a new method to compute and constrain the possible shapes of those correlation functions, assuming they were generated during inflation. This ``cosmological bootstrap” draws inspiration from the modern scattering amplitudes program in flat space, as well as the conformal bootstrap of phase transitions. After discussing primordial scalar fluctuations, I will also explain how the consistent propagation of gravitational waves imposes further constraints on the structure of spinning primordial correlators.
- Host: Lars Aalsma
- Department Coffee Hour
- Department Coffee Hour (Virtual)
- Time: 3:30 pm
- Place: Virtual (see abstract for connection info)
- Abstract: AIMEE N LEFKOW is inviting you to a scheduled Zoom meeting.
Topic: Department Coffee Hour
Time: Jan 29, 2021 03:30 PM Central Time (US and Canada)
Every week on Fri, until May 14, 2021, 16 occurrence(s)
Jan 29, 2021 03:30 PM
Feb 5, 2021 03:30 PM
Feb 12, 2021 03:30 PM
Feb 19, 2021 03:30 PM
Feb 26, 2021 03:30 PM
Mar 5, 2021 03:30 PM
Mar 12, 2021 03:30 PM
Mar 19, 2021 03:30 PM
Mar 26, 2021 03:30 PM
Apr 2, 2021 03:30 PM
Apr 9, 2021 03:30 PM
Apr 16, 2021 03:30 PM
Apr 23, 2021 03:30 PM
Apr 30, 2021 03:30 PM
May 7, 2021 03:30 PM
May 14, 2021 03:30 PM
Please download and import the following iCalendar (.ics) files to your calendar system.
Weekly: https://uwmadison.zoom.us/meeting/tJMkf-yqpjojHdRt7HGeqviWNpBBgTH6ardi/ics?icsToken=98tyKuCvpzMvGNyUuR6HRowEHYqgZ-rxiH5EgqdviEjNJCVCdArBGPJgELVLOI7R
Join Zoom Meeting
https://uwmadison.zoom.us/j/97985281970?pwd=alp0enRHWmR2SnlxM2g3cCttdTU4Zz09
Meeting ID: 979 8528 1970
Passcode: 309601
One tap mobile
+13126266799,,97985281970#,,,,*309601# US (Chicago)
+19292056099,,97985281970#,,,,*309601# US (New York)
Dial by your location
+1 312 626 6799 US (Chicago)
+1 929 205 6099 US (New York)
+1 301 715 8592 US (Washington D.C)
+1 346 248 7799 US (Houston)
+1 669 900 6833 US (San Jose)
+1 253 215 8782 US (Tacoma)
Meeting ID: 979 8528 1970
Passcode: 309601
Find your local number: https://uwmadison.zoom.us/u/adjU8aKij2
Join by SIP
97985281970@zoomcrc.com
Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia)
149.137.40.110 (Singapore)
64.211.144.160 (Brazil)
69.174.57.160 (Canada)
207.226.132.110 (Japan)
Meeting ID: 979 8528 1970
Passcode: 309601
- Host: Climate and Diversity Committee