URI Physics Colloquium
The URI Physics department hosts an ongoing speaker series each academic year, which features physics experts from URI and other universities, as well as scientific organizations.
During the fall and spring semesters, colloquia are held in East Hall, Room 112. Refreshments are served about half hour before each talk.
All are welcome, and there is no fee to attend.
Schedule for Fall 2026 :
| Date | Speaker | Affiliation | Title | Location | Time | Zoom link |
|---|---|---|---|---|---|---|
| September 11, 2026 | Student Presentations | URI | East 112 | 4:00PM | Zoom Link | |
| September 18, 2026 | Student Presentations | URI | East 112 | 4:00PM | Zoom Link | |
| September 25, 2026 | Chris Lirakis | Near Term Future of Quantum Computing | East 112 | 4:00PM | Zoom Link | |
| October 2, 2026 | Chiara Mingarelli | Yale | Searching for merging supermassive black holes | East 112 | 4:00PM | Zoom Link |
| October 9, 2026 | Begüm Kabagoz | MIT | Observing and Evading Quantum Back-Action on a Kilogram-Scale Oscillator | East 112 | 4:00PM | Zoom Link |
| October 16, 2026 | Jeff Gore | East 112 | 4:00PM | Zoom Link | ||
| October 23, 2026 | Student Presentations | URI | East 112 | 4:00PM | Zoom Link | |
| October 30, 2026 | Nimmi Sharma | Central Connecticut State University | Illuminating The Atmosphere: Lidar Techniques for Pollution, Weather, and Climate | East 112 | 4:00PM | Zoom Link |
| November 6, 2026 | Student Presentations | URI | East 112 | 4:00PM | Zoom Link | |
| November 13, 2026 | Mehran Kardar | MIT | Boundaries, inclusions and disorder in active matter | |||
| November 20, 2026 | Asad Hussain | Flatiron | ||||
| December 4, 2026 | Herman Sintim | University of Notre Dame | East 112 | 4:00PM | Zoom Link | |
| December 11, 2026 |
Abstracts:
Near Term Future of Quantum Computing
by Chris Lirakis
Abstract: Quantum Computing is still very nascent. The notional idea of quantum computers was postulated by Richard Feynman. Feynman’s statement that if you were to model quantum mechanics you’d need a quantum computer. Modern digital computers offer a level of abstraction along with libraries which does not fully exist for Quantum Computers. The compute power offered by quantum computers is realized when the algorithm can take advantage of the quantumness or Hamiltonian you are given. In this talk we will review some of the applications that are currently being explored and those that are gaining the most traction. The primary applications that are making progress are in quantum chemistry. As a sub domain to quantum chemistry there are applications into battery development, corrosion, organic chemistry in the biological field as examples. Other applications include high energy physics, finance, CFD, and so on. We should also consider that small quantum computations can also be useful. To set realistic expectations, the user should consider what potential advantage can be gained through a classical-quantum system and consider the full system problem.
Searching for merging supermassive black holes
by Chiara Mingarelli
Pulsar timing arrays have opened a new observational window onto nanohertz gravitational waves, providing evidence for a gravitational wave background and motivating the search for the individual supermassive black hole binaries that generate it. In this talk, I will present the first catalog of targeted searches using the NANOGrav 15 year data set, focusing on 114 active galactic nuclei with observed periodicity or other indications of binarity. By incorporating source specific information such as sky position, distance, redshift, and an estimated gravitational wave frequency, our limits on strain and chirp mass are improved on average 2.6x compared to all sky analyses. I will discuss how these searches connect to population models, electromagnetic follow-up, and current measurements of the gravitational wave background. The tests outlined here create a path toward the first detection of an individual supermassive black hole binary with pulsar timing arrays.
Observing and Evading Quantum Back-Action on a Kilogram-Scale Oscillator
by Begüm Kabagoz
Abstract: Quantum back-action is a fundamental limitation in precision quantum measurements. LIGO is a particularly suitable platform for studying this because classical noise sources have been suppressed far enough that quantum noise limits much of its observation band. Shot noise limits how precisely we measure the test-mass motion, while fluctuations in optical power exert radiation-pressure forces on the 40-kg mirrors. The same light therefore measures the mirrors and pushes on them, giving rise to measurement imprecision and back-action.
In this talk, I will describe an experiment in which we use feedback to induce an effective optomechanical resonance in LIGO’s differential arm motion, defining a mechanical mode. We then control the quantum optical reservoir interacting with this mode using frequency-dependent squeezed states. The quadrature composition and correlations of this reservoir determine how it drives the mechanical system. By engineering these correlations, we partially cancel the contribution of quantum back-action in the measurement and reduce the observed displacement noise around the mechanical resonance by approximately 47%.
Interpreting this measurement requires separating how much of the observed displacement is actual motion, including quantum back-action, and how much comes from measurement imprecision. I will describe a framework that decomposes LIGO’s full quantum-noise model into imprecision, back-action, and their cross-correlation, allowing us to identify the origin of the observed suppression. Writing the problem in this form also suggests a different way to think about LIGO: not only as a complicated interferometer whose quantum noise must be modeled by inferring a daunting number of parameters, but as a controllable quantum measurement system with many available experimental degrees of freedom. I will end by discussing how those degrees of freedom can be used to move toward programmable quantum measurements in which the input state, interaction, and readout are designed together.
Illuminating The Atmosphere: Lidar Techniques for Pollution, Weather, and Climate
by Nimmi Sharma
The atmosphere contains suspended particulates called aerosols which can have profound effects on human health, air quality, weather and climate. The vertical distribution of these particulates is hard to characterize, yet information on aerosol distributions and properties are essential for atmospheric studies. Lidar, also known as laser radar has been an important tool for profiling aerosols as a function of altitude and time. We discuss a novel inexpensive lidar system that has been developed to address challenges faced by traditional backscatter lidars for aerosol remote sensing. We also present examples of measurements made with this system and applications of lidar techniques for atmospheric characterization.
Boundaries, inclusions and disorder in active matter
by Mehran Kardar
Abstract: Active systems are driven out of equilibrium by exchanging energy and momentum with their environment. This endows them with anomalous mechanical properties which leads to rich phenomena when active fluids are in contact with boundaries, inclusions, or disordered potentials. Indeed, studies of the mechanical pressure of active fluids and of the dynamics of passive tracers have shown that active systems impact their environment in non-trivial ways, for example, by propelling and rotating anisotropic inclusions. Conversely, the long-ranged density and current modulations induced by localized obstacles show how the environment can have a far-reaching impact on active fluids. This is best exemplified by the propensity of bulk and boundary disorder to destroy bulk phase separation in active matter, showing active systems to be much more sensitive to their surroundings than passive ones.
Bio: Mehran Kardar is the Francis Friedman Professor of Physics at MIT. Born and educated through high school in Tehran (Iran), he obtained a BA degree from Cambridge University (UK) in 1979, and a PhD in Physics from MIT in 1983. He was a Junior Fellow of the Harvard Society of Fellows for three years, before joining MIT faculty in 1986. Kardar’s research spans statistical physics, including soft matter, disordered systems, biophysics, and nonequilibrium phenomena; he is also the author of two widely used textbooks in the field. His honors include the A.P. Sloan Fellowship, Presidential Young Investigator Award, Guggenheim Fellowship, and the Alexander von Humboldt Foundation Research Award. Kardar is a Fellow of the American Physical Society and the American Academy of Arts and Sciences, a member of the National Academy of Sciences, and recipient of the Boltzmann Medal and the 2026 Onsager Prize.