Events at Physics |
Events on Monday, March 31st, 2025
- Academic Calendar
- Spring Semester classes resume
- Abstract: *Note: actual end time may vary.*
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Effects of magnetic geometry and neutrals in gyrokinetic simulations of magnetized boundary plasmas
- Time: 12:00 pm - 1:15 pm
- Place: 1227 Engineering Hall
- Speaker: Tess Bernard, General Atomics
- Abstract: Successful fusion pilot plant (FPP) design hinges upon the ability to predict and control exhaust conditions, to maximize the lifetime of plasma-facing components. This work describes a pathway toward high-fidelity, first-principles simulations with predictive capabilities for plasma particle fueling and detachment. It presents the coupling of a continuum full-f gyrokinetic turbulence model with a 6D continuum model for kinetic neutrals, carried out using the Gkeyll code, which has been extended to include general geometry capabilities using a canonical Poisson Bracket formalism. A successful exhaust design will rely on both neutral interactions and plasma shaping in order to reduce the flux of heat and particles to the divertor without degrading core plasma conditions. We explore these effects through simulations of DIII-D inner-wall-limited (IWL) plasmas. For example, negative triangularity plasmas exhibit good confinement properties without the presence of disruptive edge localized modes (ELMs). We present the differences in profiles and turbulence dynamics in negative and positive triangularity geometries. Results demonstrate good agreement with experimental data.
- Host: Prof. Adelle Wright
- Theory Seminar (High Energy/Cosmology)
- Generalized symmetry constraints on deformed 4d (S)CFTs
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Craig Lawrie, DESY, Hamburg
- Abstract: I explore the consequence of generalized symmetries in four-dimensional N=1 superconformal field theories. First, we classify all possible supersymmetric gauge theories with a simple gauge group that have a nontrivial one-form symmetry and flows to a superconformal field theory. Upon identifying unbroken discrete zero-form symmetries from the ABJ anomaly, we find that many of these theories have mixed zero-form/one-form 't Hooft anomalies. Then we classify the relevant deformations of these SCFTs that preserve the anomaly. From this mixed anomaly together with the anomalies of the discrete zero-form symmetries, we find obstructions for the relevant deformations of these SCFTs to flow to a trivially gapped phase. I will also study non-Lagrangian SCFTs formed by gauging copies of Argyres-Douglas theories and constrain their deformations. In particular, I highlight a new duality between the diagonal gauging of two D3(SU(N)) theories and SU(N) gauge theory with two adjoints. I conclude with some comments on non-supersymmetric deformations of our work. Event recording:
- Host: Gary Shiu
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Astrophysical Neutrinos Uncover Neutrino Properties and Decode New Physics
- Time: 3:30 pm - 6:00 pm
- Place: 5280 Chamberlin
- Speaker: Anna Suliga , New York University
- Abstract: Even with only Standard Model interactions, neutrinos play a critical role in core-collapse supernovae, cooling the proto-neutron star, setting the conditions for nucleosynthesis, and likely powering the explosion. Their effects could be immensely more profound in the presence of new physics, often poorly constrained by laboratory experiments alone. In this talk, I will discuss the effects of the strong lepton number violating neutrino self-interactions (LNV νSI) on the infall phase of the core-collapse supernova evolution. Strong LNV νSI processes equilibrate all neutrino seas; hence, all neutrino species share a common temperature and chemical potential. The new lowered electron neutrino chemical potential renders increased electron captures. I will show how strong LNV vSI could alter the standard supernova collapse scenario. Unlike many existing studies focusing on the late evolution effects, this study simulated the impact of LNV vSI on the infall phase with a full analytic treatment. The rapid neutrino-antineutrino equilibration leads to entropy generation and enhanced electron capture that may impact star evolution and the emitted neutrino signal. Timely DUNE neutrino detectors can also independently probe this new physics.
- Host: Baha Balantekin