.Colloquium Events
Fall 2022
The Supermassive Black Hole – Galaxy Connection
Speaker: Jonelle Walsh (Texas A&M University)Host: Casey Papovich
Over the past 20 years it has become increasingly clear that supermassive black holes are essential components of galaxies, as demonstrated by the correlations connecting black hole masses and large-scale galaxy properties. Although about ~100 dynamical black hole mass measurements have been made to date, the local black hole mass [...]
Virus symmetry-breaking, elasticity and self-assembly
Speaker: Roya Zandi (University of California, Riverside)Host: Rainer Fries
Spherical crystals are elementary models of geometric frustration in materials, with important realizations in a range of systems from viral shells and fullerenes to particle- and molecular-coated droplets. Using continuum elasticity theory, we study the structure and elastic energy of ground states of crystalline caps conforming to a spherical surface. [...]
Cavity Quantum Electrodynamics And Quantum Measurement
Speaker: Luiz Davidovich (Texas A&M University/Federal University of Rio de Janeiro (Brazil))Host: Roland Allen
The strong interaction between an atom and an electromagnetic field confined to a cavity, as well as the ability, demonstrated in several labs, to control the interaction of a single atom with a single photon, has stimulated theoretical and experimental developments concerning new devices, like the micromaser, high-precision quantum sensing, [...]
Hunting for new physics with neutron decay
Speaker: Leendert Hayen (North Carolina State University)Host: Dan Melconian
The Standard Model of particle physics is our most successful theory ever constructed. Even so, there are a number of profound open questions, such as the nature of dark matter, neutrino masses and the inclusion of gravity which remain unanswered. Additionally, several internal consistency tests show tension with Standard Model [...]
September 22, 2022
4:00 pm – 5:00 pm (CDT)
When Stars Attack! Near-Earth Supernova Explosions Revealed by Deep-Ocean and Lunar Radioactivity (Remote Only)
Speaker: Brian Fields (University of Illinois Urbana Champaign)Host: Louis Strigari
Supernova explosions are multimessenger particle engines, theycreate many of the elements essential for planets and life, and theyplay central roles in galaxy evolution. Yet these awesome eventstake a sinister shade when they occur close to home, because anexplosion nearby can pose a grave threat to Earthlings. We willshow how radionuclides [...]
Time-reversing a laser: What it means and what it’s good for
Speaker: A. Douglas Stone (Yale University)Host: Alexey Belyanin
Over a decade ago an overlooked symmetry of Maxwell’s equations coupled to matter was discovered. The linear Maxwell wave equation in the presence of a gain medium can describe a laser at threshold. This is the point at which gain balances loss and the system self-organizes to oscillate coherently at [...]
A Case Study in Nuclear Proliferation – The Iran Nuclear Deal and the Responsibility of Physicists
Speaker: Matthias Grosse Perdekamp (University of Illinois Urbana Champaign)Host: Rainer Fries
The first nuclear weapon was tested in Alamogordo, NM, in July 1945. In the following month, Hiroshima and Nagasaki were destroyed through the explosion of two nuclear warheads. These horrifying strikes directly led to the surrender of Japan almost 4 years after its attack on Pearl Harbor. An industrial scale [...]
Molecular Spectroscopy at the Limit of Spatial Resolution (Special Date and Time!)
Speaker: Volker Deckert (University of Jena (Germany))Host: Alexey Zheltikov
Essentially all fundamental processes take place in dimensions far beyond the diffraction limit of standard optical microscopy. Consequently, almost all spectroscopic information obtained so far is based on averaged data over many molecules. While we certainly can extract useful information of such experiments, there are fundamental constraints that would render [...]
The Nature of Hot and Dense Strongly-Interacting Matter
Speaker: Andrew Steiner (University of Tennessee)Host: Jeremy Holt
Neutron stars are unique nuclear physics laboratories. Observations of isolated, accreting, and merging neutron stars can be used to probe matter from the nuclear saturation density to densities described by perturbative QCD and from sub-nuclear temperatures up to 100 MeV. I will show, for example, how neutron star observations connect [...]
“Listening” to Spin & Magnetization Noise
Speaker: Scott Crooker (Los Alamos National Laboratory)Host: Alexey Belyanin
Not all noise in experiments is unwelcome. Certain types of fundamental noise contain extremely valuable information about the system itself – a classic example being the inherent voltage fluctuations across any resistor (i.e., Johnson noise), from which temperature can be determined. In magnetic systems, fundamental noise can exist in the [...]
Is Basketball Scoring Just a Random Walk?
Speaker: Sidney Redner (Santa Fe Institute)Host: Wayne Saslow
Believe it or not, watching basketball is nearly the same as watching repeating coin tossing! By analyzing available data from recent NBA basketball seasons, basketball scoring during a game is well described by a continuous-time anti-persistent random walk, with essentially no temporal correlations between successive scoring events. We show how [...]
Brownian Markers of Quark-Gluon Plasma: From Confinement to the “Perfect Liquid
Speaker: Ralf Rapp (Texas A&M University)Host: Rainer Fries
Quantum Chromodynamics (QCD) is the well-established theory of the strong nuclear force, with quarks and gluons as the elementary degrees of freedom. However, the emergence of its most prominent phenomena, i.e., the quark confinement into hadrons and the generation of hadronic mass, remains under intense investigation. Over the last two [...]
String cosmology: From the Early Universe to Today
Speaker: Fernando Quevedo (University of Cambridge)Host: Chris Pope
We briefly review applications of string theory to cosmology, from primordial times to present-day accelerated expansion. Topics covered will include string inflation, and alternatives, the CMB,gravitational waves, cosmological moduli, dark matter candidates such as axions and primordial black holes, dark energy candidates such as de Sitter vacua and quintessence and [...]
Space-Time Through the Kaleidoscope: Applying Temporal and Multiwavelength Datasets to Supermassive Black Hole Phenomenology
Speaker: Krista Lynne Smith (Southern Methodist University)Host: Jonelle Walsh
The space-time distortion caused by supermassive black holes provides a unique laboratory for violent physical processes like stellar tidal disruption, highly relativistic jets, and turbulent accretion flows. Synthesizing observations across many wavelengths and studying their time variability at slow and rapid timescales promises a new, dynamic, thorough understanding of how [...]
Measurement of the Vacuum State as Thermal Bath Under Acceleration
Speaker: Bill Unruh (University of British Columbia and Texas A&M University)Host: Stephen Fulling
In 1975-76, I argued that the vacuum state behaved like a thermalbath to an accelerated observer. The temperature is proportional tothe acceleration, with 10^22 cm/s^2 corresponding to 1K. This isclosely related to the Hawking effect for black holes. While botheffects are extremely difficult to observe in nature, th ey can [...]
November 29, 2022
4:00 pm – 5:00 pm (CDT)
High-Energy Neutrinos: A New Trail Towards New Physics
Speaker: Carlos Arguelles Delgado (Harvard University)Host: Louis Strigari
The observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory has open up a new window to the universe. These neutrinos traverse the longest distances from their sources and have the largest energy ever observed. These neutrinos open a new trail to search for new physics that cover parameter space [...]
December 1, 2022
4:00 pm – 5:00 pm (CDT)
Why AI is Harder Than We Think
Speaker: Melanie Mitchell (Santa Fe Institute)Host: Rainer Fries
Since its beginning in the 1950s, the field of artificial intelligencehas cycled several times between periods of optimistic predictionsand massive investment (“AI Spring”) and periods of disappointment,loss of confidence, and reduced funding (“AI Winter”). Even withtoday’s seemingly fast pace of AI breakthroughs, the development oflong-promised technologies such as self-driving cars, [...]Spring 2023 & Beyond
TBA
Speaker: Heinz-Eberhard Mahnke (Freie Universitat and Helmholtz Center Berlin)Host: John Hardy
