Physics Colloquium – Gabor Csathy
KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United StatesProfessor Gabor Csathy, Department of Physics and Astronomy, Purdue University
Emergent Particles and Topology in Flat Landau Bands
Electronic systems with flat energy bands support a variety of topological phases of current interest. The two-dimensional electron gas in the fractional quantum Hall regime is such a system. Ground states of this system found an elegant description in terms of emergent particles called composite fermions.
Physics Colloquium – Marcus Noack
KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United StatesDr. Marcus Noack, Research Scientist, Lawrence Berkeley National Lab
Next-Generation Gaussian Processes for Function Approximation, Uncertainty Quantification, and Decision-Making
Gaussian processes (GPs) and Gaussian-related stochastic processes are powerful tools for function approximation, uncertainty quantification, global optimization, and autonomous data acquisition due to their robustness, analytical tractability, and natural inclusion of Bayesian uncertainty estimates. Even so, Gaussian processes are often criticized for poor approximation performance and neck-breaking computational costs in real-life applications. The reason for this gap, however, is not the methodology itself but rather a user-caused lack of flexibility and domain awareness of the underlying prior probability distribution.
Physics Colloquium – Joel Nowitzke
KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United StatesJoel Nowitzke, PhD Candidate, UW-Milwaukee
Modeling and Measurements of Network Formation and Viscoelastic Behavior of Folded Protein-Based Hydrogels
Proteins are vital for various daily functions and are even used in creating biocompatible materials through chemical crosslinking. However, predicting the mechanical properties of these materials is challenging due to the random orientation of constituent molecules within the network. Bridging the gap between nanoscopic and macroscopic scales is essential for formulating predictable biomaterials.
Physics Colloquium – Rob Pisarski
KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United StatesRob Pisarski, Distinguished Scientist, Department of Physics, Brookhaven National Laboratory
The Ugly Duckling and the Swan: The Quark-Gluon Plasma and Heavy Ion Collision
I give a pedagogical and historical overview of the search for the Quark-Gluon plasma (QGP) in the collisions of heavy ions. I begin with a brief review of why we expect a QGP to be formed at high temperature. In this, numerical simulations in lattice Quantum ChromoDynamics (QCD) form the bedrock of the field. In particular, they demonstrate the relationship between deconfinement and the restoration of chiral symmetry.
Physics Colloquium – Segev BenZvi
KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United StatesSegev BenZvi, Assoc. Professor, Department of Physics, University of Rochester
Measuring Cosmic Expansion with the Dark Energy Spectroscopic Instrument
Since the first observations of the accelerating expansion of the universe at the end of the 1990s, astronomers and physicists have struggled to understand dark energy, a mysterious repulsive force that drives the acceleration. A number of models of dark energy exist. The simplest (the cosmological constant), assumes dark energy is non-interacting and is the same everywhere in space and time. Different models predict subtely different features in the large-scale structure of the universe. We are now entering an era of new photometric and spectroscopic surveys which can discriminate different models of dark energy with unprecedented precision.