Events at Physics |
Events During the Week of November 20th through November 26th, 2022
Monday, November 21st, 2022
- Plasma Physics (Physics/ECE/NE 922) Seminar
- High-Energy Density Physics and Inertial Confinement Fusion at Los Alamos National Laboratory
- Time: 12:00 pm - 1:00 pm
- Place: 1610 Engineering Hall
- Speaker: Liz Merritt, Los Alamos National Lab
- Abstract: Abstract:
High-energy-density (HED) science is the study of ionized material under extreme pressures (> 1 Mbar), which can alter the very chemical and atomic properties of matter. Many astrophysical systems are HED, from the interiors of gas giant planets to supernovae. It is only in recent history with the development of large laser and pulsed power systems that scientists are able to create and study HED materials in the lab to gain insight into phenomena in the wider universe. In this talk we will discuss the breadth of the HED program at Los Alamos National Laboratory (LANL), with applications from the basic science of turbulence in the universe to inertial confinement fusion (ICF) efforts to create fusion energy in the lab.
Bio:
Dr. Elizabeth Merritt is a staff Scientist at Los Alamos National Laboratory where she specializes in experimental high-energy-density (HED) hydrodynamics and inertial-confinement fusion (ICF). Dr. Merritt received a B.A. in mathematics and physics from Mount Holyoke College, with a concentration in optoelectronics, and her Ph.D. in physics from the University of New Mexico in 2013, for work on plasma jets for magneto-inertial-fusion. Dr. Merritt is the PI on the LANL Planar HED Hydrodynamics campaigns including the NIF Multi-shock campaign, which is examining hydrodynamic instabilities growth and transition to turbulence under complex conditions similar to ICF capsules. Dr. Merritt is also the ICF Project Leader for the Double Shell Campaign, which is developing a platform for studying volume burn for ICF at the NIF. Finally, Dr. Merritt is actively involved in several APS-DPP early-career and diversity advocacy groups, and LANL educational outreach efforts. - Host: Plasma Physics/ECE/NE 922 seminar
Tuesday, November 22nd, 2022
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Constraining modifications of black hole perturbation potentials near the light ring with quasinormal modes
- Time: 2:00 pm - 3:00 pm
- Place:
- Speaker: Nicola Franchini , APC, Paris/CPB, Berkeley
- Abstract: In modified theories of gravity, the potentials appearing in the Schrodinger-like equations that describe perturbations of nonrotating black holes are also modified. Can these modifications be constrained with high-precision gravitational-wave measurements of the black hole's quasinormal mode frequencies? By assuming the modifications to be proportional to a small perturbation parameter, and parametrized by a Taylor expansion in M/r, we compute the quasinormal modes of the modified potential up to quadratic order in the perturbative parameter. Either through a principal component analysis or via Markov-chain-Monte-Carlo methods we try to recover the Taylor coefficients in the M/r. In both cases, even if the overall reconstruction is good, we find that the bounds on the individual parameters are not robust. Because quasinormal mode frequencies are related to the behaviour of the perturbation potential near the light ring, we propose a different strategy. We map the Taylor expansion to the value of the potential and its derivatives at the peak by using Wentzel–Kramers–Brillouin theory, and we demonstrate that the value of the potential and its second derivative at the light ring can be robustly constrained. These constraints allow for a more direct comparison between tests based on black hole spectroscopy and observations of black hole ``shadows'' by the Event Horizon Telescope and future instruments.
- Host: Baha Balantekin
Wednesday, November 23rd, 2022
- No events scheduled
Thursday, November 24th, 2022
- Academic Calendar
- Deadline for Graduate students to change variable credits
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Deadline for Graduate students to request pass/fail or credit/audit options for a Fall term course
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Thanksgiving recess
- Abstract: *Note: actual end time may vary.* University offices closed. URL:
Friday, November 25th, 2022
- Academic Calendar
- Deadline for students (except Graduate) to withdraw from Fall term
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Deadline for students to add a Fall term course with department permission
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Deadline for students to change Honors Optional course status
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Deadline for students to drop a Fall term course
- Abstract: *Note: actual end time may vary.* CONTACT: 262-3811, registrar@em.wisc.edu URL:
- Academic Calendar
- Thanksgiving recess
- Abstract: *Note: actual end time may vary.* University offices open. URL:
Saturday, November 26th, 2022
- Academic Calendar
- Thanksgiving recess
- Abstract: *Note: actual end time may vary.* University offices closed. URL: