Events at Physics
Events During the Week of November 4th through November 10th, 2018
- Plasma Physics (Physics/ECE/NE 922) Seminar
- NO SEMINAR
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Chaos & Complex Systems Seminar
- A report on the recent work by Araujo and Liotta on the topological requirements for robust perfect adaptation in networks of any size
- Time: 12:05 pm
- Place: 4274 Chamberlin (Refreshments will be served)
- Speaker: Sigurd Angenent, UW Department of Mathematics
- Abstract: From the article, Robustness, and the ability to function and thrive amid changing and unfavorable environments, is a fundamental requirement for living systems. Until now it has been an open question how large and complex biological networks can exhibit robust behaviors, such as perfect adaptation to a variable stimulus, since complexity is generally associated with fragility. Here we report that all networks that exhibit robust perfect adaptation (RPA) to a persistent change in stimulus are decomposable into well-defined modules, of which there exist two distinct classes. These two modular classes represent a topological basis for all RPA-capable networks, and generate the full set of topological realizations of the internal model principle for RPA in complex, self-organizing, evolvable bionetworks. This unexpected result supports the notion that evolutionary processes are empowered by simple and scalable modular design principles that promote robust performance no matter how large or complex the underlying networks become.
- Host: Clint Sprott
- No events scheduled
- R. G. Herb Condensed Matter Seminar
- Interaction-induced time symmetry breaking in periodically driven oscillators
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Mark Dykman, Michigan State University
- Abstract: Quantum dynamics of a periodically driven system is described in terms of the Floquet states. Generally, if the system is in a Floquet state, its dynamical variables oscillate with the period of the driving. Recently much interest have attracted systems where this discrete time-translation symmetry is broken, the “time crystal” effect. Nonlinear oscillators, including nanomechanical systems and modes in electromagnetic cavities, provide a natural platform for studying this effect. I will discuss the classical and quantum phase transitions to the broken-symmetry state in systems of coupled oscillators. Time permitting, and for completeness, I will also show time-symmetry breaking in the simplest quantum system, a qubit.
- Host: Coppersmith
- Cosmology Journal Club
- Time: 12:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details: http://cmb.physics.wisc.edu/journal/index.html Feel free to bring your lunch! If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Ross Cawthon (firstname.lastname@example.org) and Santanu Das (email@example.com).
- Astronomy Colloquium
- "Star Formation Then and Now"
- Time: 3:30 pm
- Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM. Talk Begins at 3:45 PM
- Speaker: Nia Imara, CfA Harvard
- Abstract: Stars are of fundamental importance to astronomy, and how they form and shape their environments influence everything from exoplanet studies to cosmology. Stars form in heavily obscured molecular clouds, and understanding the initial conditions of star formation persists as one of the leading challenges of contemporary astrophysics. A major challenge is the wide range of physical scales involved: from the large-scale galactic environment, to molecular clouds, to the high-density filaments and cores most directly associated with the birth of stars, and all the way down to the physics of dust, atoms and molecules. I will discuss ways to overcome these challenges, focusing on the birth of molecular clouds from the atomic interstellar medium, the role of high-density substructure in the formation of stars, and the properties of molecular clouds in dwarf galaxies. I will also explore some cosmological implications of stardust, proposing theoretical models for dust in high-redshift galaxies and in the intergalactic medium.
- Host: Professor Eric Wilcots
- No events scheduled