Events at Physics |
Events During the Week of April 13th through April 20th, 2025
Monday, April 14th, 2025
- Atomic Physics Seminar
- Hamiltonian Engineering using synthetic dimensions
- Time: 11:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Shraddha Agrawal, UIUC
- Abstract: Hamiltonian engineering can provide insights into the control and manipulation of quantum systems, which may pave the way for progress in quantum sensing and quantum many-body physics. Here, I will focus on a specific type of Hamiltonian engineering technique based on the spectroscopic coupling of atomic states. I will describe how we use two-photon Bragg resonances to couple discrete momentum states of our BEC, forming a synthetic lattice of momentum states in one dimension. Taking advantage of the site-resolved control afforded by our synthetic lattice technique, I will show some experimental results regarding transport in a one-dimensional quasiperiodic mosaic lattice. I will then discuss two-dimensional momentum state lattices. Finally, I will offer prospective directions in leveraging atomic interactions to probe many-body topological physics and squeezed states in our experimental platform.
- Host: Mark Saffman
- Plasma Physics (Physics/ECE/NE 922) Seminar
- "A Ritz variational principle for local collisionless gyrokinetic instabilities"
- Time: 12:00 pm - 1:15 pm
- Place: 1227 Engineering Hall
- Speaker: Cole Stephen, University of Texas at Austin
- Abstract: Turbulence driven by gyrokinetic instabilities is largely responsible for transport in magnetic fusion devices. To estimate this turbulent transport, integrated modeling codes often use mixing length estimates in conjunction with reduced models of the linearized gyrokinetic equation. One common method of formulating and solving the linearized gyrokinetic eigenvalue problem equation uses a Ritz variational principle, particularly in the local collisionless limit. However, the variational principle as typically stated in the literature is mathematically incorrect. In this work, we derive a mathematically correct form of the variational principle that applies to local linear collisionless gyrokinetics in general geometry with electromagnetic effects. We also explicitly derive a weak form of the gyrokinetic field equations suitable for numerical applications.
- Host: Prof. Adelle Wright
- GMaWiP
- Research Presentations
- Time: 4:00 pm - 6:00 pm
- Place: Chamberlin Hall Room 5280
- Abstract: GMaWiP and the Physics Department are hosting a low-pressure research symposium featuring talks by the following graduate and undergraduate students: Julian Beas-Gonzalez; M. Clark; Michael Martinez; Nicholas Tallon
- Host: Julia Sheffler
Tuesday, April 15th, 2025
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Inferring new properties of matter with future gravitational-wave observations
- Time: 2:00 pm
- Place: Join Zoom Meeting: Meeting ID: 965 9696 7335
- Speaker: Prof. Jocelyn Read , California State University, Fullerton
- Abstract: As the sensitivity of gravitational-wave detector networks increases, high-fidelity signal recovery from the most prominent events becomes possible. The strongest signals present both opportunities and challenges for inferring the properties of their sources. Focusing on the problem of inferring neutron star equations of state in neutron star mergers, I will discuss how systematic errors from waveform modeling have the potential to dominate the inference of matter properties in future observations. If it is properly addressed, however, subdominant effects added to the waveform model may then be revealed, providing novel opportunities to learn about neutron star matter beyond the equation of state. I will outline a data-driven approach to interpreting gravitational-wave observations with phenomenological signal corrections, including some first results from my group at CSUF. I'll also discuss methods of connecting measured waveform corrections to the energetics of the source system. Finally, I will relate these uncertainty quantification methods to goals for interferometer commissioning and instrumental design, demonstrating how next-generation sensitivities will translate into improved scientific potential.
NOTE: All participants and hosts are now required to sign into a Zoom account prior to joining meetings hosted by UC Berkeley.
- Host: A. Baha Balantekin
Wednesday, April 16th, 2025
- Climate & Diversity
- Physics Microagressions Workshop
- Time: 12:00 pm - 1:30 pm
- Place: Sterlin B343 or Zoom
- Speaker: Triston Kin, Office of Inclusion Education
- Abstract: What is a microaggression? How do we recognize them and how do we respond to them? How can we hold ourselves accountable when microaggressions are knowingly or unknowingly committed? Our microaggressions workshop shares campus research and supports participants in learning intervention skills to be a positive member of their community.
- Host: Rachel Zizmann
- Astronomy Colloquium
- Public Talk: New Worlds: Analyzing the Atmospheres of Exoplanets with the James Webb Space Telescope
- Time: 7:00 pm - 8:00 pm
- Place: 2241 Chamberlin
- Speaker: Jonathan Fortney, University of California, Santa Cruz
- Abstract: Over 6000 planets have now been found around other stars, but we only have information about what their atmospheres are like for a few dozen. NASA's powerful James Webb Space Telescope (JWST), which features a 20-foot mirror in space, is currently being used to understand atmospheres. We can look for atmospheres around rocky planets the size of the Earth, and we can measure the abundances of molecules like water, methane, ammonia, and carbon dioxide, in larger planets, of sizes similar to Neptune and Jupiter. In this talk Professor Fortney will describe the latest exoplanet results from JWST as we seek to understand these new worlds.
- Host: Melinda Soares-Furtado
- Astronomy Colloquium
- Public Talk: New Worlds: Analyzing the Atmospheres of Exoplanets with the James Webb Space Telescope
- Time: 7:00 pm - 8:00 pm
- Place: 2241 Chamberlin
- Speaker: Jonathan Fortney, University of California, Santa Cruz
- Abstract: Over 6000 planets have now been found around other stars, but we only have information about what their atmospheres are like for a few dozen. NASA's powerful James Webb Space Telescope (JWST), which features a 20-foot mirror in space, is currently being used to understand atmospheres. We can look for atmospheres around rocky planets the size of the Earth, and we can measure the abundances of molecules like water, methane, ammonia, and carbon dioxide, in larger planets, of sizes similar to Neptune and Jupiter. In this talk Professor Fortney will describe the latest exoplanet results from JWST as we seek to understand these new worlds.
- Host: Melinda Soares-Furtado
Thursday, April 17th, 2025
- R. G. Herb Condensed Matter Seminar
- Field theory of monitored, interacting fermions with charge-conservation
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Matthew Foster, Rice University
- Abstract: The dynamics of entanglement in monitored quantum circuits has opened up a new chapter in far-from-equilibrium, quantum many-body physics. Charge-conserving dynamics of 1D free fermions monitored by local charge measurements are known to possess only an area-law entangled phase, with no measurement-induced phase transition (MIPT). We formulate the more interesting problem for monitored dynamics of interacting fermions, using the Keldysh formalism. We derive a simple effective statistical mechanics model for the system. We show that, as soon as local density interactions are turned on, the volume-law entangled phase and the MIPT into an area-law phase appear, the latter described by a separatrix in the weak-coupling RG flow. Invoking general symmetry principles, our theory also naturally exhibits the “charge-fuzzy” and “‘charge-sharpened” phases, as well as the “charge-sharpening” transition of KT type, identified in previous work. We explain how the simple effective stat. mech. model that we obtain is made possible by the heating effects of the measurements, which trivialize the fermion distribution function whilst still admitting a panoply of dynamical phases and transitions.
- Host: Alex Levchenko
- High Energy Seminar
- Measuring the nucleon axial form factor in deuterium and hydrogen can’t be that hard?
- Time: 2:30 pm - 3:30 pm
- Place: CH 5280 /
- Speaker: Rik Gran, Professor Physics and Astronomy University of Minnesota Duluth, Co-spokesperson MINERvA experiment
- Abstract: In a recent paper in Nature, the MINERvA neutrino cross section experiment presented a measurement of the axial form factor of the nucleon using anti-neutrino reactions on protons (hydrogen nuclei). This is the first new nucleon data since the 1980’s bubble chamber measurements that used neutrino + neutron (in deuterium) reactions. Phenomenological nucleon form factors are essential information for two customers. They are used in the calculation of the baseline event rates for neutrino + nucleus interactions used in the search of other phenomena, such as neutrino oscillation parameters and CP violation. They can also be calculated using QCD lattice techniques, where calculations may in principle be more precise than the existing measurements. This talk will split between celebrating the 50 year history of the deuterium measurements and describing the new MINERvA measurement, with implications for current and upcoming neutrino experiments such as T2K, NOvA, SBN, and DUNE.
- Host: Brian Rebel
- Astronomy Colloquium
- New Views of Exoplanet Atmosphere Physics and Chemistry from JWST
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Jonathan Fortney, University of California, Santa Cruz
- Abstract: Giant planets and brown dwarfs are astrophysical objects with different formation locations – planets in disks and brown dwarfs (we think) in giant molecular clouds. These different objects transition across the very same range of Teff, with planets strongly influenced by their parent star’s heating from “above,” while brown dwarfs inexorably cool from their interior, which warms their atmospheres from “below.” This major energy difference can drive important differences between atmospheres. JWST has been revolutionizing our understanding of these cool atmospheres, and in this talk I will discuss a range of modeling work that aims to confront a variety of high signal-to-noise spectral observations, in particular for objects below Teff = 1000 K, where a number of major chemical transitions in these atmospheres occur. Our work uncovers a wide range of physical processes, including vertical mixing, photochemistry, and tidal heating, which can all affect the structure and chemistry of cool atmospheres. The significant diversity in spectra stress-test our models in unique ways.
- Host: Melinda Soares-Furtado
Friday, April 18th, 2025
- Climate & Diversity
- Diversity Forum Fridays! Use Plain Language to Build a More Inclusive Workplace Community
- Time: 9:00 am - 10:30 am
- Place: Chamberlin 5310 & Zoom
- Speaker: Rachel Zizmann, UW-Madison Physics
- Abstract: Ineffective communication causes workplace anxiety for 80% of US employees (SoftActivity, 2021). This can lead not only to technical issues on the job but also to feelings of isolation and disengagement in the workplace. Plain Language is content that can be understood the first time your audience reads or hears it. Using Plain Language strategies helps to avoid misunderstandings in the workplace and demonstrates respect for your audience. Clear communication can also empower employees to perform their jobs more confidently and efficiently, leading to promotions and salary increases. Plain Language strengthens the thread of belonging in a work team by encouraging clear and open communication. You will leave with both written and verbal strategies you can use immediately to build a community of trust, respect, and inclusion within your workplace.
- Physics Department Colloquium
- The Compact, High Field Mirror Path to Fusion and First Results from the Wisconsin HTS Axisymmetric Mirror
- Time: 3:30 pm - 4:30 pm
- Place: 2241 CH
- Speaker: Cary Forest, University of Wisconsin-Madison
- Host: Mark Saffman
- Academic Calendar
- Graduate School Spring 2025: Request for all Master's and Doctoral Degree Warrants
- Time: 5:00 pm - 6:00 pm
- Abstract: CONTACT: 262-2433