Physics & Astronomy Nuclear Science Seminar

Title: From massive gravity to RATs: ultra-light dark matter phenomenology with atom interferometers

Abstract: Atom interferometers offer exceptional sensitivity to ultra-light dark matter (ULDM)  through their precise measurement of phenomena acting on atoms. Previous work has established their capability to detect scalar and vector ULDM, but their potential for detecting spin-2 ULDM has until recently remained unexplored. In this talk I will introduce the sensitivity of atom interferometers to ULDM and focus on novel research for spin-2 models derived from several frameworks for massive gravity: a Lorentz-invariant Fierz-Pauli case and two Lorentz-violating scenarios. Coherent oscillations of the spin-2 ULDM field induce a measurable phase shift through three distinct channels: coupling of the scalar mode to atomic energy levels, and vector and tensor effects that modify the propagation of atoms and light. Atom interferometers uniquely probe all of these effects, while providing sensitivity to a different mass range from laser interferometers. These results demonstrate an exciting new theory target for atom interferometers and other quantum sensors to explore. I will also discuss challenges faced by these experiments from environmental noise, including atmospheric phenomena and local human and animal activity.

Date:
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Location:
CP 179
Event Series:

Physics & Astronomy Astro Seminar

Title: A novel view of the Milky Way disk and outer Solar system

Abstract: Combining big survey data with advanced statistical analysis is a fruitful approach to new discoveries. I will present two examples.   (1) One is a new mapping technique to provide for the first time a clear and flat view of the phase space of Milky Way disk. Applying it to Gaia data, we found sharp new structures with order-of-unity contrast in number density and metallicity. It opens a new window to study galactic dynamics, calling for theoretical explanation and observational search for similar structures in other disk galaxies.  (2) Another example is a new algorithm searching for moving objects from imaging survey. Applying it to cosmological surveys, I found a dwarf planet with the widest orbit in the Solar system, which places an interesting challenge to the Planet Nine / Planet X hypothesis.

Date:
-
Location:
CP 303
Event Series:

Physics & Astronomy Astro Seminar

Title: Warm ionized gas filaments in non-central early-type galaxies

Abstract: Filamentary multiphase gas is nearly ubiquitous within the brightest cluster galaxies (BCGs) of cool-core clusters and is likely related to the feeding and feedback of their supermassive black holes. Determining how such filaments form is crucial to understanding the interplay between baryon cycling, active galactic nucleus (AGN) feedback, and the evolution of early-type galaxies (ETGs). However, BCGs account for only a small fraction of all ETGs and their gaseous atmospheres are thought to be strongly influenced by the extreme, dense cluster environments in which they reside. In this talk, I will present the results of our multiwavelength analysis of 126 nearby ETGs that sit outside of the immediate cores of galaxy groups and clusters (hereafter “non-central” ETGs) - with the aim of connecting our current understanding of filamentary multiphase gas formation to the greater ETG population. Using archival VLT-MUSE observations, we detect warm ionized gas in 54 of the 126 non-central ETGs. Most of these systems (35/54) host ordered, rotating gas disks, while the remainder (19/54) show extended filamentary structures that resemble the multiphase filaments seen in BCGs. I will discuss how the MUSE data, in tandem with archival Chandra X-ray observations, support an interpretation in which the warm filaments condense out of cooling, thermally unstable hot halos. Furthermore, I will present emission-line diagnostics that test the ionization mechanisms capable of powering the filaments.

Date:
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Location:
CP 303
Event Series:

Physics & Astronomy Astro Seminar

Title: Using the Metallicity of Simulated Galaxies to Understand Galaxy Evolution

Abstract: Numerical simulations are an invaluable tool for understanding how galaxies form and evolve. Yet, the current generation of simulations suffers from significant modeling uncertainties, rooted in divergent predictions from different codes using similar prescriptions and in a lack systematic comparisons between qualitatively different models. In this talk, I will highlight the oftentimes underappreciated differences between popular cosmological simulations (e.g., IllustrisTNG, EAGLE, FIRE) through examining their metal content. Metals serve as powerful observational tracers of the galactic baryon cycle and are highly sensitive to the details of feedback physics. I will show that even for nominally similar simulation models (e.g., IllustrisTNG and EAGLE), the overall metal budget of the galaxy can be significantly different. Moreover, distinct physical implementations (e.g., IllustrisTNG and FIRE) make very different predictions for the spatial distribution of metals within galaxies. Together, these predictions provide a theoretical framework through which we can leverage the wealth of observational data on metals to gain deeper insight into the processes driving galaxy evolution.

Date:
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Location:
CP 303
Event Series:

Arts and Sciences Distinguished Faculty Awards 2025

Visiting Writers Series: Alumni Reading feat. Erika Simpson, Allegra Solomon, and Alfonso Zapata

Erika J. Simpson holds an MFA ('21) in creative writing from the University of Kentucky and is the recipient of the 2021 UK MFA Award in Nonfiction. Her essay, “If You Ever Find Yourself,” was published in Roxane Gay’s The Audacity and featured in Best American Essays 2022, edited by Alexander Chee. This Is Your Mother is her debut memoir, and she also writes fiction for the page and screen.
 
Allegra Solomon received her MFA ('22) from the University of Kentucky. Her debut short story collection, There’s Nothing Left for You Here, won the Kimbilio National Fiction prize. Her work has been nominated for the Pushcart Prize, Best of the Net, and has appeared in The Georgia Review, TriQuarterly, American Literary Review, New Ohio Review, Lolwe, and more.
 
Alfonso Zapata received his MFA ('23) in poetry at the University of Kentucky. He is the recipient of the Jim Lawless IV Poetry Prize and the 2022 & 2023 UK MFA Poetry Awards. His work has appeared in Sho Poetry Journal, and he is the author of the chapbook, Together Now (Belle Point Press, 2024). His first full-length book, To Pay for Our Next Breath, won the TRP Southern Poetry Breakthrough Prize.
Date:
Location:
Cornerstone - Esports Theater, 401 S Limestone, Lexington, KY 40508
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