Physics Colloquium – Dr. Morgan Lynch

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

Dr. Morgan Lynch, Technion – Israel Institute of Technology

A Brief History of Quantum Field Theory in Curved Spacetime

The incorporation of classical general relativity into the framework of quantum field theory yielded a rather surprising result -- thermodynamic particle production. In short, for fundamental deformations in the structure of spacetime, quantum mechanics necessitates the creation of thermalized particles from the vacuum. One such phenomenon, known as the Unruh effect, causes empty space to effervesce a thermal bath of particles when viewed by an observer undergoing uniformly accelerated motion.

In this presentation, we will review the timeline of conceptual discoveries which led to broad classes of these intriguing thermodynamic phenomena. Beginning with the original discovery of particles created by the expansion of the universe, we will cover a brief history of quantum field theory in curved spacetime, culminating in the first experimental observation of the Unruh effect, and other aspects of acceleration-induced thermality, in high energy channeling radiation.

Physics Colloquium – Mark Williamsen

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

Mark Williamsen, Quantum Design, Inc

Applications of AC Bridges in Cryogenic Measurements

AC (alternating current) bridges have proven to be useful in making precise measurements at low temperature, including thermometry as well as length change with respect to either thermal expansion (dilatometry) or applied magnetic field (magnetostriction). Techniques now in use allow one leg of the bridge to be placed at the cryogenic sample site while the other legs remain at room temperature, with the intervening temperature gradient being imposed along a length of coaxial cable.

Physics Colloquium – Daniel Vrinceanu

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

Radiative Cascade in Rydberg Atoms

This talk is an introduction to the physics of Rydberg atoms. The two complementary flavors of Rydberg atoms, high and low angular momentum states, have contrasting properties as they relate to the correspondence principle that bridges classical behavior to quantum mechanics. Dynamic symmetries allow a unified point of view to investigate this correspondence. Highly excited atoms dissipate their energy in different ways depending on their initial angular momentum: low angular momentum states make transitions in large energy increments, quickly approaching the ground state, while high angular momentum states make small steps, slowly spiraling towards lower states.

Event Series Physics Colloquium – Open

Physics Colloquium – Pierre-Alexandre Gourdain

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

The Impact of Electron Physics in High Energy Density Plasmas

The study of high energy density plasmas (HEDP) allows researchers to study the impact of microscopic phenomena on macroscopic scales by using plasmas dense enough to be probed by high energy photons (i.e. visible, UV, X-ray). This probe allows us to use readily available detectors to make precise, two-dimensional measurements of the electron density and infer the electron flow speed and magnetic field.

Physics Colloquium – Dr. Horia Petrache

Dr. Horia Petrach, Department of Physics, Indiana & Purdue Universities

Interactions of Neuromodulators with Model Lipid Membranes

Neurotransmitters and neuromodulators typically function by binding to specialized receptors in neuronal membranes. In this work, we study two different neurotransmitters that also function as neuromodulators, namely dopamine (DA) and adenosine triphosphate (ATP). Dopamine is best known as the feel-pleasure hormone while ATP is best known for being the source of energy in the cell.

Physics Colloquium – Ben Owen

Lapham 160 3209 N. Maryland Ave., Milwaukee, WI, United States

Professor Ben Owen, Department of Physics & Astronomy, Texas Tech University
Multi-messenger Astrophysics from LIGO to Cosmic Explorer

LIGO’s detections of gravitational waves from binary mergers made history and yielded insights into extreme gravity and matter. With more detections, unusual mergers will yield ever more information on new populations. What other gravitational wave signals will be detected, from LIGO to Cosmic Explorer? What physics and astrophysics will we learn from them, especially in tandem with new and planned electromagnetic astronomy facilities?

Physics Colloquium – Min Gyu Kim

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

How to see antiferromagnetic domains and domain walls
In this talk, I will introduce myself and discuss my journey as an experimental condensed matter physicist, explaining the field briefly. I will then focus on my recent research activities and interests, specifically on imaging antiferromagnetic domains and domain walls.

Physics Colloquium – Roshanak Etemadpour

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

Roshanak Etemadpour, Ph. D. candidate, Department of Physics, University of Wisconsin-Milwaukee

The title and abstract for this talk will be posted when made available.

Physics Colloquium – Francis Halzen

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

IceCube: Opening a Neutrino Window on the Universe from the South Pole
Professor Francis Halzen, Professor and Director of IceCube, Department of Physics, University of Wisconsin-Madison

Below the geographic South Pole, the IceCube project has transformed one cubic kilometer of natural Antarctic ice into a neutrino detector. IceCube detects more than 100,000 neutrinos per year in the GeV to 10 PeV energy range. From those, we have isolated a flux of high-energy neutrinos originating beyond our Galaxy, with an energy flux that is comparable to that of the extragalactic high-energy photon flux observed by the NASA Fermi satellite. With a decade of data, we have identified their first sources, which point to the obscured dense cores associated with the supermassive black holes of some active galaxies as the origin of high-energy neutrinos (and cosmic rays!).

Physics Colloquium – Helvi Witek

KIRC 1150 3135 N. Maryland Ave., Milwaukee, WI, United States

CSI Gravity: Investigating Mysteries of Fundamental Physics with Black Holes

Dr. Helvi Witek, Asst. Professor, Dept. of Physics, UIUC
Black holes are among the most exciting predictions of Einstein's theory of general relativity, composed of the fabric of spacetime itself. Observations of black holes offer unique access to extreme gravity, and they enable us to investigate long-standing puzzles in fundamental physics ranging from dark matter to the very nature of gravity itself.