PHYSICS COLLOQUIUM Fall 2024
Date and time: Thursdays 1:30 pm, see dates below
Location: 111 Smith Hall. All colloquia are in-person.
| August 22th | NO COLLOQUIUM – First Week of School |
| August 29th | NO COLLOQUIUM - First week of Labs |
| September 5 | Speaker: Jorge Lopez, University of Texas El Paso Title: Italian delicacies served up in a neutron star crust. Abstract: The study of heavy ion reactions has taught us that nuclear matter has liquid and gaseous phases, phase changes, critical behavior, and many rich phenomena. Here a summary of theoretical efforts leading to the understanding of the thermodynamics of nuclear matter will be presented, including recent ones that study possible “pasta” like structures of neutron star crusts. |
| September 12 | NO COLLOQUIUM |
| September 19 | Speaker: Nayana Shah, Washington University in St. Louis Title: Reimagining a complex quantum system: turning fermions to bosons, bosons to fermions Abstract: To explore and understand complex interacting systems, often the first step is to pose probing questions, both theoretically and experimentally, and to identify the relevant degrees of freedom for the conditions of interest. This then allows one to construct a model for the system that captures the interplay of those chosen variables. But this model may still not be amenable to theoretical analysis. One of the elegant ways to proceed is to seek a change of variables that transforms the model into a simplified form and at the same time advances the quest for identifying the emergent degrees of freedom at play. Transforming fermion fields to boson fields has been one such method of choice in low-dimensional strongly correlated quantum systems for the last five decades. Bosonization is a non-trivial transformation that in the case of the celebrated Luttinger model, transforms interacting one-dimensional fermions into free bosons and reveals the emergence of spin-charge separation. Another key paradigm for strong-coupling physics comes from the Kondo model for a localized impurity spin interacting with a conduction electron sea. Here too bosonization helps, and with additional unitary transformations leads to a solvable point. At this so-called Toulouse point, the reorganized bosons can now be transformed back to fermions to obtain a resonant-level model. After reviewing these ideas I will talk about work done over the last decade to put forth and establish a consistent way of implementing these transformations. To do so, I will share the story of its genesis in our discovery of inconsistencies and symmetry violations as we resolved a non-equilibrium transport puzzle. I will then conclude with the insights we have gained from our in-depth analysis of the multi-channel Kondo model using solvable points and renormalization group methods to compare the old/conventional and new/consistent ways of implementing the "bosonization-debosonization" program. Host: Benjamin Fregoso |
| September 26 | Speaker: Maxim Dzero, СƬƵ Title: Spontaneous synchronization: from fireflies to superconductors Host: Physics department |
| October 3rd | NO COLLOQUIUM - Fall Break |
| October 10th | NO COLLOQUIUM - APS Meeting (Division of Nuclear Physics) |
| October 17th | Speaker: Veronica Dexheimer, СƬƵ Title: TBA Host: Physics department |
| October 24th | NO COLLOQUIUM |
| October 31th | Speaker: Melanie Good, University of Pittsburgh Title: TBA Host: Peter Tandy |
| November 7th | NO COLLOQUIUM |
| November 14th | Speaker: Jonathan Selinger, СƬƵ Title: Reformulation of elasticity theory for liquid crystals and lipid membranes. Host: Physics department |
| November 21th | NO COLLOQUIUM |
| November 28th | NO COLLOQUIUM - Thanksgiving Break |
| December 5th | NO COLLOQUIUM - Week before finals |
| December 12th | NO COLLOQUIUM - Final Exam Week |