USF Physics and Astronomy Colloquium Series

The Physics and Astronomy Colloquia at the University of San Francisco are talks given by invited research scientists, on topics of current interest. The Physics Colloquium Series has been in place since 1994.

All colloquia typically start at 3:30, and will have light refreshments served. Colloquia take place in CS 303, unless otherwise noted.

colloquiumpic

Professor Douglas Osheroff (middle), 1996 Nobel Laureate in Physics, appears here on the occasion of his colloquium at USF, flanked by Professors Camblong (left) and Camperi (right).

PAST COLLOQUIUM SERIES VIDEOS

Spring 2015 Colloquium Series

February 4, 2015 - Dr. James Jee

"Gravitational Lensing and Dark Matter in the Universe"

3:30-5:00 in LCSI 210

It was only two decades ago that the reaction to the idea of measuring shape distortions of galaxies by gravitational lensing turned from skepticism to enthusiasm.  Today, the technique called weak-lensing is routinely used to study dark matter distribution in galaxy clusters, average mass profiles of galaxies, and the large scale structures in the universe.  The next decade will be the most exciting era when we start to collect accurate cosmic shear data from billions of galaxy shapes.

I will provide detailed introduction to gravitational lensing while highlighting some of the key milestones in the field.  Ambitious future multi-billion dollar projects, such as LSST, EUCLID, and WFIRST will be discussed.  I will emphasize that in order to achieve their proclaimed scientific goals, substantial amounts of concerted efforts are required to overcome systematics.  Finally, I will present my most recent results obtained from colliding galaxy clusters, which are often dubbed "cosmic particle accelerators."

 

James Jee was born in Seoul, Korea.  He received his PhD at the Johns Hopkins University in 2005 and is currently working as a senior project scientist at University of California, Davis.  His expertise is gravitational lensing.  In a recent gravitational lensing accuracy competition called GREAT3, he earned the 1st place award.  He will move to Seoul in July 2015 to take an associate professor position at Yonsei University.

 

February 11, 2015 - Dr. Alexander Grutter

"Probing Nanoscale Magnetism with Neutron Scattering at the NCNR"

3:30-5:00 in LCSI 210

The ability to probe and control magnetic nanostructures is critical to the development of next generation spin-based electronics.  Neutron scattering facilities enable magnetic studies impossible to perform elsewhere, and their unique measurement capabilities are very useful to scientists studying magnetism at the nanoscale.  In this talk, I will introduce the research reactor at the NIST Center for Neutron Research and explore the basic concepts of neutron scattering.  I will discuss some of my favorite recent experiments using polarized neutron beams to understand nanoscale magnetic interactions.  Recently, we have used polarized neutron reflectometry to demonstrate direct electric field control of magnetism confined within a single atomic monolayer in complex oxide thin films.  In another recent example, we used polarized small neutron scattering to explore magnetic domain structures in high-density arrays of magnetic nanowires. 

 

Alexander Grutter received his PhD in Materials Science and Engineering from the University of California, Berkeley in 2013.  He is currently an NRC postdoctoral fellow at the NIST Center for Neutron Research.  Current research interests include electric field control of magnetism at thin film interfaces, emergent magnetic properties in complex oxide heterostructures, the role of defects and structural distortions in determining oxide thin film properties, and probing competing interactions in novel magnetic nanostructures.

 

February 18, 2015 - Dr. Calvin Berggren

"Precision Monte Carlo Event Generation for the LHC"

3:30-5:00 in LCSI 210

 

The Geneva Monte Carlo framework is a next-generation event generator for the LHC capable of combining multiple types of higher-order calculations and parton showering in order to increase the precision that is available to experimentalists using these tools.  I outline the basic parts of the Monte Carlo program in particle physics, the kinds of problems one encounters when trying to include higher-order effects, and the way that Geneva seeks to address these.  Results for e+e- + jets compared to LEP data and for Drell-Yan production are presented.

Calvin Berggren received his PhD in Particle Physics Theory from the University of California, Berkeley in 2014.  He is currently a visiting assistant professor at Texas Lutheran University.  His research experience includes advancing the state-of-the-art for Monte Carlo event generators used by experimental collaborations at particle colliders, namely the LHC, through improved accuracy, resumption, improved error estimation, increased domain of applicability, etc; developing theoretically-motivated strategies for insightful analysis of collider data; improving capabilities of parton shower tools.

 

 

February 25, 2015 - Dr. Stephen Bailey

"How to Make a 3D Map of the Universe (and Why)"

3:30-5:00 in LCSI 210

I will describe the process of making a 3D map of the universe and our scientific motivations for doing so.  Using a relatively small telescope in New Mexico, every night the eBOSS project observes spectra of thousands of galaxies, stars, and quasars, and over the years we build up a 3D map of the locations and motions of millions of objects.  Some of these objects are so distant that the light has been traveling to us for 12 billion years (for comparison, the Big Bang was 13.7 billion years ago).  Our next generation project, DESI, will use a larger telescope and 5000 little robots to help position fiber optic cables on our focal plane, so that we can observe 50 million objects to make a more complete map.  We use these data to study the expansion of the universe and the underlying physics that describe it. 

Dr. Stephen Bailey is a project scientist at Lawrence Berkeley National Laboratory where he leads the software development efforts for current and future galaxy redshift surveys.  He enjoys converting raw data into useful data in order to study the history and fate of the universe.

March 4, 2015 - Dr. Jennie Guzman

"Testing Quantum Mechanics with Ultra-Cold Strontium Atoms"

3:30-5:00 in LCSI 210

 

Quantum field theory successfully describes three of the four known fundamental physical interactions.  Its inability to incorporate gravity, however, compels us to continue to probe for subtle deviations to its predictions.

Here, I discuss our plans to build an experiment to search for small violations in one of the most fundamental pillars in the quantum field theory, the spin-statistics, theorem (SST).  THe SST states that all particles with integer spin, such as photons, obey the Bose-Einstein statistics (and are thus dubbed "bosons") and all those with half-integer spin obey Fermi-Dirac statistics (and are thus dubbed "fermions").  Using ultra-cold strontium atoms, we will test if photons can sometimes behave like fermions by looking for a transition between two angular momentum states (J=0 and J'=1)-- a behavior forbidden by the SST.  Such a discovery would provide a new direction for the theoretical development of the basic axioms of quantum field theory and reveal an essential ingredient to a more fundamental view of the world.

 

I received my PhD from UC Berkeley in 2012.  For my graduate work, I studied quantum magnetism and quantum phase transitions in rubidium Bose-Einstein condensates.  After graduating, I took a post-doctoral position at Sandia National Laboratory in Livermore, California, where my research centered around using ultra-cold atoms as remote sensors.  Then in the fall of 2013, I took on a position as an assistant professor in physics at CSU East Bay, where I am currently leading an experiment aimed at searching for small violations in the spin-statistics theorem.

 

March 11, 2015 - Dr. John McGuire

"Title TBD"

3:30-5:00 in LCSI 210

Abstract TBD

 

Bio TBD 

 

April 8, 2015 - Dr. Daniel Fisher

"Title TBD"

3:30-5:00 in LCSI 210

 

Abstract TBD

Bio TBD

April 29, 2015 - Dr. Aaron Parsons

"Title TBD"

3:30-5:00 in LCSI 303

 

Abstract TBD

 

Bio TBD