Events at Physics |
Events on Friday, May 1st, 2026
- Academic Calendar
- Last Class Day
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Thesis Defense
- Taking Inventory of the Most Promising Lensed Radio Sources for Constraining Fundamental Properties of Dark Matter
- Time: 12:00 pm - 2:00 pm
- Place: 5280 Chamberlin or
- Speaker: Michael Martinez, Physics PhD Graduate Student
- Abstract: While Dark Matter (DM) makes up roughly 80% of the total matter in the Universe, its microscopic properties remain one of the biggest questions in Cosmology today. Fortunately, those properties dictate the distribution and form of macro-scale gravitational structures in the universe, allowing for indirect studies which can distinguish between competing particle models. One such avenue for this research is via strong gravitational lensing systems, where dark halos in the lens substructure and along the line of sight perturb image positions and flux. However, the current population of sources suitable for this analysis is limited, especially at radio wavelengths where astrometric perturbations are observable. I will first discuss which properties of lens systems make them especially useful for DM constraints and examine the minimum amount of information necessary for such an experiment. Then, I present the results of two successful searches for new radio lenses in existing radio and optical surveys, utilizing a new method to expand the potential follow-up population for Dark Matter studies in the future. I conclude with a discussion of the completeness of this population.
- Host: Keith Bechtol
- Physics Department Colloquium
- Building a quantum computer out of single photons and single atoms (coffee & cake to follow the lecture)
- Time: 2:00 pm - 3:00 pm
- Place: Chamberlin 2241 -
- Speaker: Josiah Sinclair, Carl & Brynn Anderson Assistant Professor of Physics, UW - Madison
- Abstract: Investiture lecture for the Assistant Professor Josiah Sinclair as the Carl and Brynn Anderson Professor of Physics. Coffee & Cake to follow the lecture at 3 PM in the lobby!
- Host: Mark Saffman
- Physics Department Colloquium
- Anderson, Lin, Lawler annual Lecture (inaugural)
- Aerosol Nexus in the Stratosphere
- Time: 3:30 pm - 4:30 pm
- Place: 2241 Chamberlin Hall -
- Speaker: David Fahey, NOAA, Director of the Chemical Sciences Laboratory
- Abstract: Stratospheric aerosols play a central role in Earth's radiative balance and atmospheric chemistry. A variety of sources both natural and anthropogenic influence the background aerosol abundance and cause extreme events. Important examples are volcanic eruptions, space traffic and wildfires. Understanding this central role requires a focus on a variety of sources with stratospheric observations and modeling studies that include chemistry, composition, microphysics, radiation and transport; hence the aerosol nexus. Initiated by Congressional mandate, NOAA’s Earth Radiation Budget (ERB) program was established to study aerosol sources and aerosol processes in the troposphere and stratosphere. ERB includes stratospheric aerosol injection (SAI)—the concept of increasing Earth’s albedo by enhancing stratospheric aerosol—which is emerging internationally as a pressing, albeit controversial, research priority. The Chemical Sciences Laboratory is pursuing fundamental research related to stratospheric aerosols through innovative instrumentation, platform use, observations and modeling, supported in part by the ERB program. I will provide some context to the program and present selected research highlights, including the role of SAI in the Montreal Protocol Scientific Assessment of Ozone Depletion. I am honored in giving this presentation because the guidance and mentoring I received from Professors Anderson, Lin, and Lawler, and the Physics Department, had exceptional influence in my formative years.
- Host: Thad Walker
- Physics Department Awards Banquet
- Time: 5:30 pm - 9:00 pm
- Place: Wisconsin Institute for Discovery
- Host: Kevin Black