Events During the Week of April 12th through April 19th, 2026
Monday, April 13th, 2026
- Theory Seminar (High Energy/Cosmology)
- Constructibility of Massive Helicity Amplitudes and the ALT Shift
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Zhen Liu, Minnesota U.
- Abstract: Recursive constructions in amplitudes are a strong feature that requires careful analytic continuation with momentum shift to yield the full, correct, physical amplitudes. If not done systematically, an undetermined contact term would arise. We study the All-Line Transverse (ALT) shift, which we developed for on-shell recursion of amplitudes for particles of any mass. Our method allows for a nice and clean determination of the constructibility of the underlying theory. We apply the shift to the QED, electroweak theory, and higher-spin Compton scattering. The ALT shift framework allows consistent treatment in dealing with contact term ambiguities for renormalizable massive and massless theories, which we show can be useful in studying real-world amplitudes with massive spinors.
- Host: Joshua Foster
Tuesday, April 14th, 2026
- Physics Education Innovation Forum
- Physics Education Innovations at UW Madison
- Time: 1:00 pm - 2:00 pm
- Place: B343 Sterling Hall and on Zoom
- Speaker: Ayshea Banes, Isaac Barnhill, Mihir Manna, and Abdollah Mohammadi, UW Madison Department of Physics
- Abstract: This month we have updates on projects in physics education that are being led by people in the Department of Physics. These studies have the potential to improve physics and other courses at UW and elsewhere. Please join us in learning about them and providing helpful comments. Ayshea Banes: My research explores ways to center Blackness within the physics classroom and how this may transform the Eurocentric pedagogy currently used to one that is culturally relevant and community-based. Another topic I researched (with Erika Marin-Spiotta, Dept. of Geography) was ways that anti-Blackness (more commonly known as white supremacy) appear within physics education and how by identifying its exclusionary mechanisms/assimilationist norms may lead to roads of Black liberation. Isaac Barnhill (with Josh Weber & Peter Timbie): This experiment makes a controlled comparison between two different styles of instructional physics lab activity: traditional labs which aim to reinforce content learned in the course lectures, and experimentation labs which aim to teach students the role of experimentation in science broadly, and physics in particular. The study uses data from Physics 202 students to explore how students’ personal views on the nature and utility of experimentation are impacted by their lab curriculum and whether the new curriculum affects student exam scores. Mihir Manna (with Ben Spike): Our research is centered on supporting strategic problem-solving approaches by students in Physics 103. Specifically, we are writing new discussion problems that encourage students to choose their own high-level strategies, rather than following a traditional “fill in the blanks” structure that can limit student agency. We hope that these prompts will help students gain a better appreciation for the usefulness of physics principles, generalize such approaches to other contexts, and feel more self-confident in their problem-solving ability. Abdollah Mohammadi: will present the results of a recent survey on the use of artificial intelligence (AI) tools in our physics service courses, mainly 103, 104, 201, 202, 207, and 208. The survey explores how students engage with AI for learning, problem-solving, and testing their understanding, as well as their perceptions of its benefits and limitations. Key findings highlight trends in AI adoption, including its role in enhancing conceptual understanding, improving efficiency in coursework, and raising concerns about academic integrity. The results also reveal variations across different course levels and backgrounds. These findings could be useful to discuss and come up with some best practices for incorporating AI in a way that supports learning while maintaining rigorous academic standards.
- Host: Josh Weber
- Atomic Physics Seminar
- System-Level Quantum Networking: Entanglement, Metrology, and Quantum Memory in Deployed Fiber Systems
- Time: 3:00 pm - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Dr. Jing Su, University of Maryland
- Abstract: We present a system-level approach to quantum networking that integrates entanglement distribution, precision metrology, and quantum memory in deployed fiber environments. Polarization-entangled photons are distributed over stabilized links with active feedback control, achieving high visibility and robust channel uptime. Network-compatible calibration techniques, including synchronized power measurements and remote detector calibration, enable accurate and scalable system characterization. Ancilla-assisted process tomography (AAPT) is employed to characterize quantum processes and quantify channel performance with high fidelity, supporting stable multi-node operation. In parallel, electromagnetically induced transparency (EIT)–based quantum memory in cesium vapor cells is studied, with anti-relaxation coatings significantly improving storage efficiency and coherence time. Together, these results demonstrate a practical and scalable framework for real-world quantum networks.
- Host: Mark Saffman
Wednesday, April 15th, 2026
- No events scheduled
Thursday, April 16th, 2026
- R. G. Herb Condensed Matter Seminar
- Title to be announced
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Maxim Khodas , Hebrew University of Jerusalem
- Host: Alex Levchenko
- Astronomy Colloquium
- Single-lined Eclipsing Binary Stars: A Stellar Astronomy Multi-Tool
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Prof. Daniel Stevens, UMN-Duluth
- Abstract: Precisely and accurately measured stellar properties such as mass and radius are important for a wide range of science cases, from characterizing nearby exoplanets to inferring properties of distant galaxies. Double-lined eclipsing binary stars (DLEBs) have long been the gold standard for making such measurements, as the two similar-luminosity stars’ individual masses and radii can routinely be measured to percent-level precision. By combining space-based observations from the TESS and Gaia space telescopes with archival datasets, it is now possible to measure fundamental stellar parameters precisely and accurately for single-lined EBs (SLEBs), in which only the more luminous star’s spectrum is seen. I will summarize the advantages of studying SLEBs for specific science cases, focusing on recent efforts by my research group and others to resolve the longstanding problem of radius inflation in low-mass stars. I will also highlight a few “superlative” SLEB discoveries and their potential for probing stellar physics across the HR diagram. I will discuss the obstacles we have encountered to characterize SLEBs to percent-level precision and accuracy, then preview the near-term prospects for overcoming them.
- Host: Thomas Beatty
Friday, April 17th, 2026
- Physics Department Colloquium
- Title to be announced
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: Alex Kamenev , FTPI-UMN
- Host: Alex Levchenko
