By Francis Von Mann
LEXINGTON, Ky. (September 3, 2025) - The energy on campus is palpable. Every fall, new Wildcats arrive from across the Commonwealth and beyond to begin a new chapter in Lexington.
Title: Distributed and Online Methods in Quantile Regression
Abstract: Quantile regression offers a versatile framework for modeling heterogeneous effects, but modern big data present significant computational and methodological challenges. This talk will trace a line of research on distributed and online approaches for quantile regression and related problems. In this talk, I will discuss a sequence of developments in distributed and online approaches for quantile regression, drawing connections to both classical estimation strategies and more recent advances in causal inference. I will highlight key ideas, recent progress, and future directions, with an emphasis on algorithmic insights and their relevance for large-scale applications.
Dr. Adam Smercina, Space Telescope Science Institute
Title: A New Era of Galaxy Evolution using Resolved Stars
Abstract: The varied and dynamic evolutionary histories of galaxies give rise to their stunning diversity in the present-day universe. Inferring these histories requires accessing the information encoded in their longest-lived visible components: stars. We are in an exciting new frontier, with a fleet of current and upcoming observatories capable of accessing the resolved stellar populations within and around external galaxies. In this talk, I will first summarize my efforts to chart the merger histories of nearby galaxies by surveying the stars in their accreted halos, including the exciting potential of the upcoming Roman Space Telescope. I will then discuss my efforts to trace the evolution of these galaxies star formation and structure, particularly as a consequence of their merger histories, through high-resolution surveys of their main bodies. In particular, I will highlight several large programs with JWST, which has opened up an exciting new frontier for this science. Over the next decade, these efforts with JWST and Roman have the potential to transform our view of galaxy evolution. To close, I will discuss how this current pioneering work with JWST will pave way for the next paradigm shift in resolved star science: the Habitable Worlds Observatory.
Title: TBA
Abstract: TBA
Dr. Roger Pynn, Indiana University Bloomington
Title: What are Entangled Neutrons, Anyway?
Abstract: For more than 75 years, neutron scattering has been a powerful tool for probing the positions
and dynamics of atoms, as well as the magnetic fields that shape material properties. In
parallel, advances in light optics have increasingly harnessed the quantized nature of photons
to achieve higher precision and uncover new phenomena. Can similar quantum ideas be
applied to neutrons? Remarkably, the spin, momentum, and energy of individual neutrons can
indeed be placed into entangled, Bell-like states. In this talk, I will describe how such
entanglement has been realized experimentally, and how we validated its existence.
The challenge now is to exploit these mode-entangled neutrons to access new forms of
information. Recent theoretical work suggests that entangled neutrons could uniquely probe
electron spin entanglement in specific systems—though experimental confirmation remains to
be achieved. Still, entanglement has already enabled measurements that would have been
impossible otherwise. As one example, I will present the first observation of a giant Goos–
Hänchen effect for matter waves and indicate prospects for applying similar techniques to
materials of scientific and technological relevance. Looking forward, these methods will be
especially valuable at the next-generation neutron source now being planned at Oak Ridge
National Laboratory.
Speaker: Dr. Xiaomeng Liu (Cornell)
Title: Superconductivity and Ferroelectric Orbital Magnetism in Semimetallic Rhombohedral Hexalayer Graphene
Abstract: Rhombohedral multilayer graphene has emerged as a promising platform for exploring correlated and topological quantum phases, enabled by its Berry-curvature-bearing flat bands. While prior work has focused on separated conduction and valence bands, we probe the semimetallic regime of rhombohedral hexalayer graphene. We uncovered a rich phase diagram dominated by flavor-symmetry breaking and an electric-field-driven band inversion. Near this inversion, we find a superconducting-like state confined to a region with emergent electron and hole Fermi surfaces. In addition, two multiferroic orbital-magnetic phases are observed: a ferrovalley state near zero field and a ferroelectric state at large fields around charge neutrality. The latter shows electric-field-reversible magnetic hysteresis, consistent with a multiferroic order parameter.
