Physics Colloquia

Shashwat Sardesai, PhD Candidate, UWM Physics

Cosmic Orchestra: The Gravitational Wave Background

In the last year and a half, the North American Nanohertz Observatory for Gravitational Waves, and their collaborators, have detected the presence of a gravitational wave background using pulsar timing arrays. These gravitational waves likely arise from supermassive black hole binaries (SMBHBs) and have periods spanning years or decades.

In this talk, I will go over the basics of PTAs, the different methods to analyze the background, as well as the projects I have worked on as a member of the NANOGrav collaboration to try and resolve aspects of the GWB.

The event flyer is available here.

Sheng Ran, Assistant Professor of Physics, Washington University

Strongly Correlation and Topology in Kondo Lattice Systems

Quantum materials with both strong correlations and nontrivial band structure topology can have novel physics properties that do not exist in the non-correlated counterparts. Recent theoretical work has demonstrated that combination of Kondo physics and nonsymmorphic crystal symmetries can give rise to such strong correlated topological systems.

In this talk, I will present our recent experimental exploration this direction. In one case, we found intrinsic anomalous Hall effect that seems to break the Fermi liquid scaling relation. In another case, we have discovered a candidate for topological Kondo insulator.

The event flyer is available here.

Speaker: Gabriel Freedman, PhD Candidate – UWM Physics Low-frequency Gravitational Wave Searches and Data Analysis with Hamiltonian Sampling The pulsar timing array community has found evidence for a correlated stochastic signal following the Hellings-Downs pattern indicative of an isotropic stochastic …

Speaker: Ned Budisa, Professor & Research Chair, Dept. of Chemistry, University of Manitoba Expanding the Genetic Code via Directed Evolution: Tools for Biophysicists, Materials Science, and Beyond Reprogramming the genetic code to include non-canonical amino acids (ncAAs) is a powerful …

Speaker: Dr. Katey Alatalo, Assistant Astronomer, Space Telescope Science Institute The Life-cycle of Gas in Dying Galaxies Modern day galaxies populate a bimodal distribution, in both morphology and color space. Their morphological and color properties are also inter-related, with lenticular …

Speaker: Justin A. Trujillo, PhD Candidate - UWM Physics Implementing Novel Data Analysis Methods to Enhance Biophysical Studies Studying the structure, motions, and interactions of proteins as they perform their functions is greatly important in biophysics research. Time-resolved serial femtosecond …

Early Warning of Gravitational Waves from Neutron Star Mergers
Amanda Baylor
Graduate Student
University of Wisconsin-Milwaukee

For the past decade, ground-based gravitational-wave observatories have been making detections of ripples in the fabric of spacetime from the mergers of black holes and neutron stars. Mergers involving at least one neutron star could also produce electromagnetic counterparts which may reveal new insights into the physics of these astrophysical phenomena. However, if electromagnetic observatories are not pointed at the location of the source prior to merger, we miss vital information about the physics of merger.

Detecting & Measuring Gravitational Waves in Current and Future Observatories

Pratyusava Baral
Graduate Student
University of Wisconsin-Milwaukee

Low-latency (near real-time) detection of gravitational waves (GW) is crucial for multimessenger astronomy. I contribute to maintaining and operating the GstLAL-based search pipeline, a flagship detection pipeline used by the LIGO-Virgo-KAGRA collaboration, for the present observing run (May 2023 - ongoing).

Due to circumstances beyond our control, the Physics Colloquium for Friday, 11/7/2025 is cancelled.

Justin Goodrich, Brookhaven National Laboratory

Due to circumstances beyond our control, the Physics Colloquium for Friday, 11/14/2025 has been cancelled.

Jong-Woo Kim, Argonne National Lab