Events During the Week of October 26th through November 2nd, 2025
Monday, October 27th, 2025
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Operation and Performance of the Centrifugal Mirror Fusion Experiment
- Time: 12:00 pm - 1:00 pm
- Place: 2241 Chamberlin Hall
- Speaker: Carlos Rovero-Talamas, University of Maryland, Baltimore County
- Abstract: The Centrifugal Mirror Fusion Experiment (CMFX), a research effort led by UMBC in partnership with the University of Maryland, College Park, has been funded since 2020 by ARPA-E to test the physics of centrifugal mirrors and demonstrate magnetic confinement at parameters relevant to sustained fusion production. The CMFX is the second-generation centrifugal mirror at Maryland, but the first one in the world to use superconducting coils, with a maximum field of 3-T. It is also the first one to achieve sustained operation (limited only by the passive cooling of components). Temperatures, densities, and momentum confinement times in CMFX are now high enough to produce small amounts of fusion energy when experimenting with deuterium plasmas. The applied voltages result in supersonic E x B rotation, with velocities in the azimuthal direction exceeding 1,700 km/s in deuterium plasmas. The high velocities also generate flow shear and heating, resulting in total sustained neutron productions estimated at 10^7 neutrons per second. These neutron rates indicate plasma temperatures must be around 1 keV for plasma densities of 2 – 4 x 10^18 m^-3. Neutral gas can be added in bursts during plasma discharges, leading to an increase in density and neutron production that slowly decays with confinement times of tens to hundreds of milliseconds. Experiments are underway with two He-3 detectors to time-resolve the neutron production with respect to applied voltage, and to spatially resolve the plasma region producing the neutrons.
- Theory Seminar (High Energy/Cosmology)
- Taming Axion Rotation: Dark Vector-like Confinement for Axiogenesis
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Pouya Asadi, UC, Santa Cruz
- Abstract: I show that extending the Standard Model with two axions and a dark vector-like confining gauge group can simultaneously account for both the observed dark matter abundance and the baryon asymmetry of the Universe - a step toward resolving the matter coincidence problem. Starting from a review of sphaleron dynamics, I derive both (i) the axion-induced contributions to fermion asymmetries and (ii) the back-reaction of these fermion asymmetries on axion-like fields, which manifests as a friction on the axions. This analysis clarifies why the minimal axiogenesis scenario cannot produce the correct dark matter and baryon abundances simultaneously. We then show that introducing a second axion and an additional vector-like dark confining sector - a natural infrared realization in the well-motivated axiverse frameworks - resolves this tension by providing a distinct source of friction in the axion dynamics. Finally, we discuss possible UV completions of this setup in extra-dimensional models of high-quality axions. Beyond its cosmological implications, this framework motivates searches for the QCD axion and predicts complementary Light-Shining-through-Wall signatures probing the second axion in the ~eV mass range. Event recording:
- Host: Lisa L Everett
- Preliminary Exam
- Scalable autotuning of high-temperature quantum dot spin qubits
- Time: 2:00 pm - 4:00 pm
- Place: B343 Sterling or
- Speaker: Tyler Kovach
- Abstract: Developing automatic, scalable hardware control is a universal challenge when assembling the physical qubit layer of a large quantum computer. For quantum dot spin qubits—a semiconductor-based platform notable for its high device tunability and its compact size—one key hurdle arises from device non-uniformity. An example of this non-uniformity is the trapped charges in the device’s oxide layers, which induce offset voltage shifts on gate electrodes. These unknown offsets need to be accounted for and calibrated away before any qubits are formed. In this talk, I will introduce a streamlined, five-step physically intuitive algorithm for initializing and bootstrapping these devices, allowing for fully autonomous calibration and characterization. Next, I will demonstrate this methodology experimentally at a high temperature of 1.3K using our in-house developed automatic tuning system, BATIS (Bootstrapping Autonomously Testing Initialization System), to configure a four quantum dot Si/SiGe hetero-structure device. Finally, I will discuss our on-going development of FAlCon (Framework for Algorithmic Control), a soon-to-be open-source software platform designed to facilitate the design, deployment, sharing, and testing of quantum dot tuning algorithms. FAlCon’s platform-agnostic architecture addresses a critical bottleneck in quantum dot scalability, paving the way for the broader implementation of large quantum dot arrays.
- Host: Mark Eriksson
Tuesday, October 28th, 2025
- Black and Brown in Physics
- General Meeting - Halloween Board Games + Relaxing
- Time: 2:00 pm - 3:30 pm
- Place: Sterling B343
- Abstract: It has been a super busy and stressful time for all of us, so we have decided to make our upcoming event be a Halloween themed board-games and chill general meeting! This event will take place this upcoming Tuesday (10/28) at 2 PM in Sterling B343. We plan to bring a bunch of Halloween themed snacks and scary board games for people to eat and enjoy. We also encourage everyone to come dressed in their Halloween costumes and contribute to the event by bringing their own spooky-themed board games (the executive members are planning to bring board games so no pressure on bringing your own games). We hope that this event will give you the opportunity to relax and recharge before the end of semester madness.
This event is open to all students, staff, faculty, and postdocs.
- Council Meeting
- Physics Council Meeting
- Time: 3:00 pm - 4:00 pm
- Place: 2314 Chamberlin
- Speaker: Kevin Black, UW - Madison
- Host: Kevin Black
Wednesday, October 29th, 2025
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Universe under the Lens: Exploring Galaxy Evolution and Cosmology through Strong Lensing and Machine Learning
- Time: 12:00 pm - 1:00 pm
- Place: 5280 Chamberlin & Zoom:
- Speaker: Sreevani Jarugula, Fermilab
- Abstract: Strong gravitational lensing is a powerful probe that provides high-resolution views of the early universe and valuable insights into the nature of dark matter and dark energy. In this talk, I will present my analysis of high-redshift, lensed dusty star-forming galaxies observed with Atacama Large Millimetre/submillimetre array (ALMA). These early galaxies offer valuable insights into early galaxy evolution. I will discuss detections of molecular water and carbon monoxide emission lines, used to infer key physical properties of these galaxies. To recover intrinsic source properties, I will introduce an image-plane lens-modeling framework tailored for interferometric data from radio and submillimeter telescopes. The second part of my talk will focus on machine learning applications for cosmology and telescope operations. I will present simulation-based inference with neural ratio estimators to constrain cosmological parameters from lensing images, essential for analyzing thousands of systems expected from surveys such as Rubin LSST. I will also highlight machine learning models that identify and filter defective images to ensure reliable Rubin data processing. Together, these studies demonstrate how strong lensing and machine learning can jointly advance our understanding of galaxy formation and the dark universe.
- Host: Sridhara Dasu
Thursday, October 30th, 2025
- Astronomy Colloquium
- Black Hole Mergers in AGN Disks: Dynamics, Electromagnetic Counterparts, and Multimessenger Signatures
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Dr. Yihan Wang, UW-Madison
- Abstract: The coalescence of stellar-mass black holes embedded in active galactic nucleus (AGN) disks offers a unique channel for compact binary formation and a promising site for multimessenger astrophysics. Gas torques, migration traps, and disk-driven accretion can dramatically alter binary evolution, potentially enhancing merger rates relative to the field population. In this talk, I will discuss recent progress on the dynamical and hydrodynamical processes that govern black hole pairing and coalescence in AGN disks, emphasizing how disk environments shape mass ratios, spin alignments, and merger timescales. I will also explore potential electromagnetic (EM) counterparts arising from gas interactions before, during, and after merger, ranging from prompt flares to long lived afterglows. By connecting theoretical models with gravitational wave observations from LIGO–Virgo–KAGRA and forthcoming detections by LISA, I will highlight how AGN-assisted mergers could serve as key laboratories for studying black hole growth, accretion physics, and galaxy evolution.
- Host: Nicholas Stone
Friday, October 31st, 2025
- Preliminary Exam
- Performance Characterization of the IceCube Upgrade and Detection of First Neutrinos
- Time: 1:15 pm - 3:15 pm
- Place: Chamberlin Hall Room 5310
- Speaker: Delaney Butterfield
- Abstract: The IceCube Upgrade is an extension of the existing IceCube Neutrino Observatory and will be deployed in the upcoming 2025/2026 austral summer. The instrumentation volume, consisting of seven new strings, will be 200 times more densely instrumented than IceCube to target lower energy atmospheric neutrino interactions. The additional strings will feature new optical modules, which will more than triple the number of PMT channels in the detector. In this presentation, I describe the new detector configuration and discuss my work on the low-level data flow. More PMT channels and more sensitive modules result in a higher data rate up the long cables of the detector leading to the surface. To reduce this data rate, we have introduced a new step in the data flow known as the "Pre-Trigger." Unique to the Upgrade, the Pre-Trigger represents the first step in deciding which PMT signals to keep when building events. In addition to my work on the in-ice data flow, I will present my initial studies on characterizing the early data we expect to see from the new strings, and my work towards performing a full analysis of a detector verification and commissioning sample of new data from the IceCube Upgrade. This analysis will highlight atmospheric neutrino events in the 3-50 GeV energy range which we would not see without the Upgrade, and how this early dataset will set the stage for future analyses.
- Host: Albrecht Karle
- Physics Department Colloquium
- Stellar Graveyards and Shifting Paradigms in Gravitational-wave Astrophysics
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: Imre Bartos, University of Florida
- Abstract: Gravitational-wave astronomy has transformed our understanding of the universe’s most extreme objects. In less than a decade, the LIGO and Virgo observatories have revealed a rich population of merging black holes and neutron stars, uncovering systems that challenge long-standing expectations from stellar evolution. We now see black holes that are heavier, more numerous, and sometimes more complex than any previously known, hinting at environments where they can collide, merge, and grow repeatedly. One such environment may lie in the accretion disks of active galactic nuclei, which can act as cosmic “stellar graveyards” that serve as black-hole assembly lines. In these dense, gas-rich regions, black holes may form binaries, merge multiple times, and even produce electromagnetic or neutrino counterparts. In this talk I will first review how gravitational-wave discoveries have reshaped astrophysics, highlighting what we have learned about compact objects and their origins. I will then explore how the AGN-disk scenario may represent the next paradigm shift, connecting gravitational waves and electromagnetic radiation into a unified multimessenger picture.
- Host: Ke Fang