Events at Physics
Events on Thursday, December 3rd, 2020
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
- Astronomy Colloquium
- "A Predictive Theory of Star Formation and Turbulence Driving Across Cosmic Time"
- Time: 11:00 am
- Place: Zoom meeting (see Abstract ) meet the students at 10am, coffee and tea at 10:45am
- Speaker: Blakesley Burkhart, Rutgers/Flatiron Institute
- Abstract: The interstellar medium (ISM) is a multiphase environment where magnetohydrodynamic (MHD) turbulence affects many key processes that govern the evolution of galactic disks include star formation.
In this talk, I shall present an overview of new analytic models connecting turbulence, star formation, feedback, and disk instability. I will show that the turbulence in discs can be powered primarily by star formation feedback, radial transport, or a combination of the two. From scales of giant molecular clouds (GMCs), I will demonstrate how the star formation efficiency can be analytically calculated from our understanding of how turbulence, gravity, and stellar feedback induce density fluctuations in the ISM via a probability distribution function analysis. This analytic calculation predicts star formation rates and star formation efficiency from pc size scales (GMCs) to kpc size scales in galaxies and provides predictions for upcoming high-z JWST observations.
Zoom Link information
Meeting ID: 885 1389 6776
- Host: Professor Alex Lazarian
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Search for pp → ttc, ttt and btb at the LHC as Probe of Top-changing Extra Higgs Bosons
- Time: 11:00 am
- Place: Zoom:
- Speaker: George W.S. Hou , National Taiwan University
- Abstract: With the absence of New Physics at the LHC or elsewhere, we argue that a general two Higgs doublet model (g2HDM) with extra Yukawa couplings as the compelling ― and accessible ― New Physics. The exotic H, A and H+ bosons should be sub-TeV in mass, but well-hidden from our view so far by
1) fermion mass-mixing hierarchy,
2) alignment (small h(125)-H mixing), and
3) (the mysterious) near-diagonal d-type extra Yukawa coupling matrix.
We give a general perspective on search strategies at the LHC, focusing on extra top Yukawa couplings, both top changing and conserving, of the exotic Higgs boson. These couplings connect with electroweak baryogenesis and the electron electric dipole moment, and there is a plethora of other flavor observables. At the LHC, we advocate the cg → ttc, ttt and btb production processes, and urge experimental search.
- Host: Kevin Black
- Cosmology Journal Club
- Time: 12:00 pm
- Abstract: Cosmology Journal Club is virtual this semester.
Each week, we start with a couple scheduled 15-20 minute talks about one's research, or an arXiv paper. The last ~20 minutes will typically be open to the group for anyone to discuss an arXiv paper.
All are welcome and all fields of cosmology are appropriate.
Contact Ross Cawthon, cawthon@wisc, for more information.