Events at Physics |
Events on Monday, March 17th, 2025
- Plasma Physics (Physics/ECE/NE 922) Seminar
- "Uncertainty quantification in fusion power plant design”
- Time: 12:00 pm - 1:15 pm
- Place: 1227 Engineering Hall
- Speaker: Enrique Miralles-Dolz , PPPL/UW-Madison
- Abstract: The characterization and quantification of uncertainties are fundamental activities in engineering design, often carried out within the framework of probability theory. While probability theory is successful for capturing aleatory uncertainties, it imposes too strict assumptions when dealing with epistemic uncertainty. In this talk I will present recent developments in methodologies for dealing with epistemic uncertainty in uncertainty quantification, sensitivity analysis, optimization under uncertainty, and risk analysis with an application to fusion power plant design.
- Host: Prof. Adelle Wright
- Department Meeting
- Closed Department Meeting
- Time: 12:15 pm - 1:00 pm
- Place: VIRTUAL - Lefkow will send link
- Closed meeting to discuss personnel matters—pursuant to Section 19.85(1)(c) of the Wisconsin Open Meetings Law
- Host: Kevin Black
- Theory Seminar (High Energy/Cosmology)
- Observable CMB B-modes from Cosmological Phase Transitions
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Gordan Krnjaic, Fermilab
- Abstract: A B-mode polarization signal in the cosmic microwave background (CMB) is widely regarded as smoking gun evidence for gravitational waves produced during inflation. Here we demonstrate that tensor perturbations from a cosmological phase transition can produce a B-mode signal whose strength rivals that of testable inflationary predictions across a range of observable scales. Although phase transitions arise from causal sub-horizon physics, they nevertheless exhibit a white-noise power spectrum on super-horizon scales. Power is suppressed on the large scales relevant for CMB B-mode polarization, but it is not necessarily negligible. For appropriately chosen phase transition parameters, the maximal B-mode amplitude can compete with inflationary predictions that can be tested with current and future experiments. These scenarios can be differentiated by performing measurements on multiple angular scales, since the phase transition signal predicts peak power on smaller scales. Event recording:
- Host: Dan Hooper