Events at Physics |
Events During the Week of February 13th through February 20th, 2022
Monday, February 14th, 2022
- Public Research Seminar
- From Astronomy to Chemistry: Towards a continuous path for the origins of life
- Time: 9:00 am - 10:00 am
- Place: Wisconsin Institutes for Discovery , Orchard Room
- Speaker: Zoe Todd, University of Washington
- Abstract: Perhaps the most intriguing question that has mystified mankind for centuries is: “are we alone in the universe?” Fortunately, we have unprecedented access to the one planet where we know life originated: the Earth. By studying the origins of life and using the context of the early Earth planetary environment, we may be able to constrain prebiotic chemical processes and understand the implications for the potential habitability of other worlds. My work addresses the origins of life from the planetary perspective; in particular, I aim to elucidate a continuous and plausible path for the origins of life: from the simplest molecules available abundantly in planetary environments, to the synthesis of the building blocks of life, and finally to the development of self-replicating protocells. By using a combined astronomical and chemical perspective within the planetary context, we can place constraints on and evaluate the plausibility of prebiotic chemical pathways; this information can be used to determine plausible environments for the origins of life. In this way, we not only gain a better understanding of how the origins of life on Earth may have occurred, but we are also better informed when it comes to the search for life on other planets.
On the Web:
- Host: David Baum,Professor and Chair, Department of Botany, Wisconsin Institute for DIscovery Fellow
Tuesday, February 15th, 2022
- Academic Calendar
- Election Day
- Time: 7:00 am - 8:00 pm
- Abstract: Primary election for School Board, County Supervisor, and Judges. Primary election if there are more than 2 candidates, for School Board, County Supervisor, and Judges. Go to MyVote.wi.gov to find your polling place, see what is on your ballot, and check your registration. If you are not registered at your current address, you can register at your polling place on Election Day. See vote.wisc.edu for information on registration and voter ID. (The final election for these contests will be April 5.) CONTACT: malischke@wisc.edu URL:
- R. G. Herb Condensed Matter Seminar
- Quantum randomness: from chaos to quantum computing
- Time: 10:00 am - 11:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Bin Yan, Los Alamos National Laboratory
- Abstract: The development of quantum technologies has now become a global race owing to its great promise to revolutionize our ability for information processing. On the other hand, the influence of quantum information science has concurrently penetrated into research areas of fundamental physics as well. In this talk, I will thus focus on a topic at the interface between Physics and Quantum Information. Specifically, I will present our approach to the study of quantum chaos from a quantum information point-of-view, and explore the implications of chaotic dynamics on the performance of quantum machine learning. Notably, quantum chaos is of fundamental interest and is crucial for answering several key questions in condensed matter physics, e.g., thermalization in isolated many-body systems. Similarly, quantum machine learning offers an appealing synergistic approach for combining and utilizing the potentials of machine learning and quantum computers. The interplay between these fields demonstrates how technical toolkits developed in Quantum Information can be applied to study problems in Physics, and vice versa insight from physics can strengthen our understanding of the limitations of quantum information processing. I will conclude this talk with a discussion about several relevant ongoing and future directions, including quantum networking and quantum correlations in quantum material.
- Host: Robert McDermott
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Multi-messenger astronomy with high-energy neutrinos
- Time: 2:00 pm - 3:00 pm
- Place: Join Zoom Meeting Meeting ID: 912 3071 4547
- Speaker: Anna Franckowiak, DESY & U. of Bochum
- Abstract: Cosmic rays are charged particles (mainly protons) that bombard the Earth from all directions reaching energies up to 10 million times what can be achieved by the most powerful man-made accelerator, the LHC. Their origin is difficult to trace, because cosmic rays are deflected by magnetic fields on their journey from their source to Earth. However, cosmic rays produce gamma-ray photons and neutrinos in interactions with matter and photon fields in or close to their source. Being neutral those secondary particles can travel undeflected and ultimately point back to the source. While gamma rays are not solely produced in interactions of cosmic ray protons, neutrinos provide a smoking-gun signature for acceleration of protons (or heavier nuclei). A diffuse flux of cosmic neutrinos was first discovered by the cubic-kilometer-sized IceCube detector located at the South Pole in 2013. I will present the ongoing search for the origin of those neutrinos using multi- messenger studies and discuss promising candidate sources with a focus on the new promising neutrino source class of tidal disruption events. Join Zoom Meeting Meeting ID: 912 3071 4547
- Host: Baha Balantekin
- Multi-messenger astronomy with high-energy neutrinos
- Time: 2:00 pm
- Place: Join Zoom Meeting Meeting ID: 912 3071 4547
- Speaker: Anna Franckowiak , DESY/Ruhr University Bochum
- Abstract: Cosmic rays are charged particles (mainly protons) that bombard the Earth from all directions reaching energies up to 10 million times what can be achieved by the most powerful man-made accelerator, the LHC. Their origin is difficult to trace, because cosmic rays are deflected by magnetic fields on their journey from their source to Earth. However, cosmic rays produce gamma-ray photons and neutrinos in interactions with matter and photon fields in or close to their source. Being neutral those secondary particles can travel undeflected and ultimately point back to the source. While gamma rays are not solely produced in interactions of cosmic ray protons, neutrinos provide a smoking-gun signature for acceleration of protons (or heavier nuclei).
A diffuse flux of cosmic neutrinos was first discovered by the cubic-kilometer-sized IceCube detector located at the South Pole in 2013. I will present the ongoing search for the origin of those neutrinos using multi-messenger studies and discuss promising candidate sources with a focus on the new promising neutrino source class of tidal disruption events.
Join Zoom Meeting
Meeting ID: 912 3071 4547
- Host: Baha Balantekin
Wednesday, February 16th, 2022
- Physics ∩ ML Seminar
- Fast and Credible Inference with Truncated Marginal Neural Ratio Estimation
- Time: 11:00 am - 12:15 pm
- Place: Chamberlin 5280 (Zoom link also available for online participants who signed up on our mailing list)
- Speaker: Alex Cole , University of Amsterdam
- Abstract: Across fields, scientific models are computationally implemented via parametric stochastic simulators. However, solving the “inverse problem” and constraining model parameters from data is a challenge in this context. Recently, the field of simulation-based inference has made great strides thanks to deep learning methods. I will outline a new method in simulation-based inference called Truncated Marginal Neural Ratio Estimation (TMNRE). TMNRE is (i) simulation-efficient, actively identifying the relevant regime of parameter space without sacrificing amortization (ii) scalable to high-dimensional data and model parameter spaces (iii) trustworthy, in the sense that statistical consistency tests beyond those available to e.g. MCMC can be rapidly performed. I will show examples of these benefits in the context of cosmological inference. I will also describe our development of a user-friendly and general package for TMNRE called swyft. Implementation of TMNRE available at Talk based on (NeurIPS ML4PS ’20), (NeurIPS ’21), .
- Host: Gary Shiu
- Department Meeting
- Time: 12:15 pm - 1:15 pm
- Place: B343 Sterling
- Speaker: Mark Eriksson, UW-Madison, Department of Physics
- Host: Mark Eriksson
Thursday, February 17th, 2022
- R. G. Herb Condensed Matter Seminar
- Tuning dipolar interactions between molecules for novel dynamics
- Time: 10:00 am - 11:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Jun-Ru Li, JILA, NIST and University of Colorado, Boulder
- Abstract: Ultracold polar molecules possess rich internal structure and support dipolar interactions, bringing new opportunities for studying quantum phenomena. Complete control of molecular quantum systems has long been hindered by chemical reactions. In this talk, I will describe results emerging from our recent implementation of exquisite control of the molecular interaction processes. By using an electric field-induced shielding resonance, we suppress the two-body reactive loss in a three-dimensional gas by a factor of 30 while preserving the strong dipolar elastic collisions. In a quasi-two-dimensional geometry where the molecular motion is constrained, we demonstrate that such loss is suppressed by aligning dipoles perpendicular to the plane of motion and exploiting the repulsive channel of the dipolar interactions. Implementing these techniques brings molecular gases into a new regime where elastic collisions dominate, leading to rapid dipolar thermalization and direct evaporative cooling to quantum degeneracy. A feature of the dipolar interaction is its long interaction range. Recently, we have created a stack of two-dimensional layers of molecules where we can control the states of the molecules in each individual layer. We directly observed and controlled interactions between molecules in and between these isolated layers. These research results have brought molecular control to a new regime, highlighting the promise of ultracold molecular gases as a new platform for quantum science.
- Host: Mark Saffman
Friday, February 18th, 2022
- Physics Department Colloquium
- The key symmetries of superconductivity
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Daniel Agterberg, UW-Milwaukee
- Abstract: Research in superconductivity has intensified recently, fueled by the promise of new quantum Majorana particles. Key to this are the symmetries of the superconducting state. In this talk, I will discuss the central role of time-reversal and inversion symmetries in stabilizing superconductivity and the unusual physical properties that arise when these symmetries are broken. The emphasis will be on the nature of the two-electron bound states, that is the Cooper pairs, that underlie superconductivity.
- Host: Alex Levchenko