Physics and Astronomy Colloquium
Dr. Alec Tewsley-Booth
Postdoctoral Research Associate
Department of Physics and Astronomy
University of Kentucky
Host: Renee Fatemi and Tim Gorringe
Title: The Second Results from the Fermilab Muon g-2 Experiment
Abstract: On August 10th, 2023, the Muon g-2 Collaboration presented a new experimental value of the positive muon magnetic anomaly, aμ = (gμ - 2)/2. From this data set, the first analyzed since our release in 2021, we determine aμ = 116592057(25) x 10-11. This result dominates the new experimental world average, aμ = 116592059(22) x 10-11, which includes the 2021 result and the final result from Brookhaven in 2006. This talk will cover the experimental apparatus and analysis techniques used to produce the newest result, especially the improvements made that led to the factor of two improvement over the 2021 result. Additionally, we will cover the state of the theory and its tension with experiment, as well as the contributions from the University of Kentucky.
Yuanyuan Su
Assistant Professor
Department of Physics and Astronomy
University of Kentucky
Host: Gary Ferland and Tom Troland
Title: Studying galaxy clusters in multiwavelength, multiscale, and multidisciplinary
Abstract: As the largest gravitational bound systems in the Universe, galaxy clusters are one of the most important probes for testing the standard cosmological models. A typical galaxy cluster contains hundreds to thousands of member galaxies. The space between these galaxies is filled with hot and diffuse plasma -- the intracluster medium (ICM), which constitutes 90% of the baryonic mass and emits strongly in X-rays primarily through bremsstrahlung. ICM provides unique laboratories to study many astrophysical processes, such as the interaction between the hot baryons and the supermassive black hole, the growth of large scale structure, and the enrichment processes of the Universe. In this talk, I will present our recent discovery on galaxy clusters from its centers to the outskirts including the multiphase gas at the brightest cluster galaxies, bow shock in merging clusters, and the chemical composition of the ICM. Our work on active galactic nuclei in cluster member galaxies and machine learning applications will also be discussed.
Prof. Susan Gardner
Department of Physics and Astronomy
University of Kentucky
Host: Brad Plaster
Title: QCD for New Physics Searches at the Sensitivity Frontier
Abstract:
Questions that drive searches for physics beyond the Standard Model include the physical origin of the cosmic baryon asymmetry and of dark matter. Quark dynamics, as realized through the theory of quantum chromodynamics (QCD), can appear in these studies in very different ways. In this talk, I develop these possibilities explicitly, first describing the role of QCD in ultra-sensitive searches for new physics, particularly at low energies, and then turning to how its features could be exploited in describing the undiscovered universe, along with the essential observational and experimental tests that could confirm them.
Professor Joe Straley
Department of Physics and Astronomy
University of Kentucky
Host: Brad Plaster
Title: TBA
Abstract: TBA
The 2023 Andrew Chamblin Memorial Colloquium
http://andrewchamblin.org/lecture.html
Speaker: Dr. Vijay Balasubramanian
Professor
University of Pennsylvania
Title: The entropy of black holes
Abstract: One of the most famous results of twentieth-century physics states that black holes carry an entropy proportional to the area of their horizons. This entropy formula is universal in general relativity: it applies to black holes with any mass, charge, or rotation, and in any spacetime dimension. I will describe a recent proposal explaining the microscopic origin and universality of this formula. The proposal exploits new developments in the study of many-body chaos, thermalization, and quantum dynamics, along with concepts of complexity and information from theoretical computer science, communications theory, and cryptography. These developments also suggest that the interior of a black hole is causally accessible to external observers, but only if they can perform egregiously complex measurements that are inaccessible under normal conditions.
Speaker: Patricia Rankin
Professor and Department Chair
Arizona State University
Department of Physics
Host: Plaster
Title: Physics is Fun! Everyone should do it
Abstract: Patricia Rankin became a physicist because she enjoyed it. She still enjoys it. She remembers being asked as a student why more women didn’t study physics. She can now give a much better answer to that question. This talk looks at how physicists solve problems, and why how we think impacts the demographics of our field. She will discuss how our understanding of what makes people leave physics has evolved and why the focus is now on a process driven approach. She will argue that while the field would benefit from more diversity, what matters to an individual is that they get to do what they enjoy and feel welcome.
Dr. NandiniTrivedi
Professor
Ohio State University
Host: Murthy
Title: Fractionalized excitations in Quantum Spin Liquids and their Detection
Abstract: The 2022 Nobel prize celebrates the detection of entanglement between two photons. Quantum spin liquids (QSLs) are long-range entangled states of matter of billions of interacting qubits or spins that develop in a Mott insulator. The fate of the interacting spins can progress along two paths as the temperature is lowered: the spins can undergo long range ordering, spontaneously breaking the continuous symmetries, leading to a magnetic phase; or the spins can remain disordered but get quantum mechanically entangled with long range patterns of many-body entanglement in the resultant QSL. The possibility of obtaining QSL phases is enhanced by having a low spin and enhanced quantum fluctuations, and frustration arising from the lattice geometry and/or competing spin-spin interactions. Remarkably QSLs harbor fractionalized excitations rather than the conventional spin waves of ordered magnets that carry integer units of angular momentum. In my talk I will identify detectable signatures of these fractionalized excitations in experiments using light and neutrons. These fractionalized excitations are promising candidates to create logical qubits for quantum computation.
Dr. Heidi Wu
Assistant Professor
Boise State University
Host: Su
Title: Probing Cosmic Acceleration with Galaxy Clusters
Abstract: The accelerated expansion of the Universe is one of the biggest puzzles in physics: Why is gravity repulsive rather than attractive on distance scales larger than a few million lightyears? Cosmic acceleration slows down the growth of structure, and we can use galaxy clusters — the largest gravitationally bound objects in the Universe — to probe the nature of cosmic acceleration. In this talk, I will first introduce our current understanding of the Universe. I will then discuss how we use sky surveys of galaxy clusters to measure cosmic acceleration and how several ambitious ground- and space-based missions will revolutionize our understanding of the Universe.
Speaker: Geoff Greene
Professor Emeritus
University of Tennessee
Host: Crawford
Title: The Life and Death of the Free Neutron
Abstract: The decay of the free neutron is the simplest example of nuclear beta decay and, as such, is the archetype for a wide variety of Weak Interaction processes. These include radioactivity, Big Bang Nucleosynthesis, and energy production in the sun. Additionally, The precise value of the free neutron lifetime, can, along with other data, be used to test the consistency of the Standard Model. Remarkably, the value of neutron lifetime can also help determine the atmospheric composition of Venus. Given the breadth of physics involved, it is disconcerting to note that, at present, measurements of the neutron lifetime by different methods are inconsistent. In this talk, I will discuss the physics of neutron decay and will review the strategies for the experimental determination of the neutron lifetime. I will discuss some of the experimental challenges and will attempt to provide some illumination of the current discrepant situation.
Title: Electrify Everything!
Abstract: Making everything run on electricity is a necessary step in the transition from fossil fuels. Starting that process immediately is also necessary, and helpful both to the process and the environment.