Physics Commons^™

Red Noise Suppression In Pulsar Timing Array Data Using Adaptive Splines, Yi-Qian Qian, Yan Wang, Soumya Mohanty

Physics & Astronomy Faculty Publications

Noise in Pulsar Timing Array (PTA) data is commonly modeled as a mixture of white and red noise components. While the former is related to the receivers, and easily characterized by three parameters (EFAC, EQUAD and ECORR), the latter arises from a mix of hard to model sources and, potentially, a stochastic gravitational wave background (GWB). Since their frequency ranges overlap, GWB search methods must model the non-GWB red noise component in PTA data explicitly, typically as a set of mutually independent Gaussian stationary processes having power-law power spectral densities. However, in searches for continuous wave (CW) signals from resolvable …

Time-Evolved Constant Voltage Conductivity Measurements Of Common Spaceborne Polymeric Materials, Brian Wood, David King, Jr Dennison

Journal Articles

Long-duration current measurements were made for low-density polyethylene (LDPE), polyimide (PI), polyether ether ketone (PEEK), and biaxially oriented polypropylene (BOPP) to determine their bulk conductivity near room temperature as a function of time. These common thin-film spacecraft material samples were vacuum baked to remove moisture and volatile contaminants to better simulate space conditions. The constant voltage conductivity (CVC) method used a very stable, low-noise dc voltage source and measured the resulting current in a parallel plate geometry. Due to the extremely low conductivity of these four polymeric materials, extended experiments of up to ten days were necessary to establish equilibrium …

Relational Observables, Quiddities, And Structural Realism, Emily Adlam

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this article, I argue that modern spacetime physics causes problems for a number of traditional accounts of modality, but also offers important new ideas about the connection between modal and non-modal features of reality. I suggest that recent work on relational observables in general relativity and quantum gravity can help us understand how non-modal features of reality could arise from modal features of reality within some form of modal ontic structural realism. In particular, I argue that the notion of an ‘internal view,’ as employed in the partial/complete observables formalism and the quantum reference frame formalism, is an important …

The Realization Of 3d Topological Spaces Branched Over Graphs, Christopher L. Duston

Physics Faculty Publications

In this paper we present an implementation of a computer algorithm that automatically determines the topological structure of spacetime, using a branched covering space representation. This algorithm is applied to a few simple examples in dimension 3, and a complete set of the topological spaces branched over several graphs are found. We also include some new visualizations of the branched covering construction, in order to aid and clarify the understanding of how these structures can be used in quantum gravity to realize the topological nature of the spacetime foam.

Optimizing Palliative Spine Radiation: A Dosimetric Comparison Of Hybrid Arc Therapy And Conventional Appa Techniques, Alaina Vaneaton

Masters Projects

This study aimed to evaluate the dosimetric impact of Hybrid Arc Palliative Radiation Therapy (HART) versus conventional anterior-posterior/posterior-anterior (APPA) beam arrangements for thoracic spine metastases. The primary objective was to assess differences in conformity, homogeneity, and organ-at-risk (OAR) sparing between the two techniques. A retrospective plan comparison was conducted using anonymized datasets from twenty patients previously treated with HART. Each case was replanned using a standard APPA technique, normalized to match the target coverage of the original HART plan within 0.1%. All plans were prescribed 20 Gy in 5 fractions. Plan quality was evaluated using conformity index (CI), homogeneity index …

The Effects Of I-127 On A High-Granularity Lii(Eu) Bonner Sphere Spectrometer Response Matrix, Adam Card, Andrew W. Decker

Student Publications

The measurement of neutron energy spectra using a Bonner Sphere Spectrometer (BSS) requires spectrum unfolding. One necessary component of spectrum unfolding is an accurate neutron response matrix, which describes the energy shift experienced by neutrons when passing through different moderation configurations prior to detection. Leveraging the recently-released ENDF/B-VIII.0 cross-section library, this work details the development of a new LiI(Eu) scintillator response matrix that features improved energy binning granularity as well as increased isotopic and statistical accuracy. Using MCNP6.2, detector responses were modeled at 105 discrete log-equi-spaced incident neutron energies from 1.000 × 10⁻⁹ to 2.512 × 10¹ MeV …

Non-Linear Atom-Laser Interactions Using Rubidium Pump-Probe Spectroscopy, Grace Neil

Beyond: Undergraduate Research Journal

An experiment was performed to demonstrate the pump-probe spectroscopy of Rubidium (Rb) vapor, revealing the nonlinear atom-laser interactions in the 5S1/2 ↔ 5D5/2 transition in Rb that can be used to generate quantum entanglement between two laser beams. The setup included a tunable infrared diode laser, optical mirrors, photodiode-detectors, a beam-splitter, and a temperature- regulated rubidium gas chamber, all of which are controlled by the TeachSpin laser controller and monitor. The output from the laser-diode was split into a pump (90%) and a signal probe (10%), which intersected in counter-propagating directions inside the Rubidium chamber. The analysis shows that in …

64th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 64th annual meeting of the Rocky Mountain Conference on Magnetic Resonance. Held in the Snowbird Resort and Conference Center, Snowbird, Utah, August 3-7, 2025.

Spatio-Temporal Variability Of San Francisco Bay Plume From Space, Piero L. F. Mazzini, Cassia Pianca, L. Fernando Pareja-Roman, Kelly L. Cole, Ryan K. Walter, Renato M. Castelao, Elias J. Hunter, Robert J. Chant

Physics

As brackish turbid waters exit San Francisco Bay, one of the largest estuaries in the U.S. West Coast, they form the San Francisco Bay Plume (SFBP), which spreads offshore and influences the Gulf of the Farallones (GoF), an ecologically significant region in the California Current System that is also home to three National Marine Sanctuaries. This paper provides the first observationally based investigation of the spatio-temporal variability of the SFBP, using a plume tracking algorithm applied to more than two decades (2002-2023) of ocean color data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard satellites Aqua and Terra. The …

Unraveling Quantum Properties Of Novel Two-Dimensional Systems Using A First-Principles Approach, Binod Regmi

Theses and Dissertations

We used first-principles density functional theory (DFT) to investigate the structural, electronic, and magnetic properties of an oxygen crystal in a copper slab, a ferrimagnetic electride with highly tunable magnetic anisotropy energy (MAE), and the Fermi surface analysis of different kagome metal phases. The Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional was used in the Vienna ab initio simulation package (VASP) for all these calculations. Because of dimensionality reduction, the electronic properties of copper change significantly at the two-dimensional (2D) scale due to whichwe observe more reconstruction in the geometry of the Fermi surface. Dimensionality reduction also influences charge transport. Moreover, we present …

Capers-Lrd-Z9: A Gas-Enshrouded Little Red Dot Hosting A Broad-Line Active Galactic Nucleus At Z = 9.288, Anthony J. Taylor, Vasily Kokorev, Dale D. Kocevski, Hollis B. Akins, Fergus Cullen, Mark Dickinson, Steven L. Finkelstein, Pablo Arrabal Haro, Volker Bromm, Mauro Giavalisco, Kohei Inayoshi, Stéphanie Juneau, Gene C.K. Leung, Pablo G. Pérez-González, Rachel S. Somerville, Jonathan R. Trump, Ricardo O. Amorín, Guillermo Barro, Denis Burgarella, Madisyn Brooks, Adam C. Carnall

Pacific Faculty Work

We present CAPERS-LRD-z9, a little red dot (LRD) that we confirm to be a z = 9.288 broad-line active galactic nucleus (BLAGN). First identified as a high-redshift LRD candidate from PRIMER NIRCam photometry, follow-up NIRSpec/PRISM spectroscopy of CAPERS-LRD-z9 from the CANDELS-Area Prism Epoch of Reionization Survey (CAPERS) has revealed a broad 3500 km s⁻¹ full width at half-maximum Hβ emission line and narrow [O iii] λλ4959, 5007 lines, indicative of a BLAGN. Based on the broad Hβ line, we compute a canonical black hole mass of log ( M BH / M ⊙ ) = 7.58 ± 0.15 , …

Antifungal Peptides From Casein Milk Of Etawa Crossbreed (Capra Hircus) As Biopreservation Agent For Bread And Molecular Docking Studies, Dian Riana Ningsih, Winarto Haryadi, Rachma Wikandari, Tri Joko Raharjo

Karbala International Journal of Modern Science

Bread without peptide fraction treatment started to grow mold on the fourth day with a total of 24x10⁷ fungi colonies/ml. Meanwhile, the addition of peptide fractions GMC5, GMC6, GMC7, and GMC8 effectively preserved bread for up to 4 days, indicated by no mold growth. The best treatment was the GMC6 peptide fraction on day 8 which grew the least amount of fungus at 7x10⁷ spores/ml. Peptide interaction with the CaATPase receptor Aspergillus sp. was carried out using HADDOCK 2.4. The 3D CaATPase structure prediction resulted in a model with good structural quality. This was supported by residues in …

Search For Higgs Boson Pair Production In The Two Light Leptons And One Tau Final State Using Proton-Proton Collision Data With $\Sqrt{S} = 13$ Tev At The Lhc From The Atlas Detector, Susan Bataju

Physics Theses and Dissertations

In this thesis, a search is presented for the pair production of Higgs bosons in a final state containing two same-charge light leptons (e/$\mu$) and one opposite-charge hadronically decaying tau lepton ($\tau_{h}$). The search is based on a data sample of proton-proton (pp) collisions at a center-of-mass energy $\sqrt{s}$ = 13 TeV, collected by the ATLAS detector during Run 2 (2015-2018) of the Large Hadron Collider (LHC), corresponding to an integrated luminosity of 140 fb$^{-1}$. The Standard Model predicts that the Higgs potential has a non-zero expectation value leading to the spontaneous breaking of electroweak symmetry and when some fundamental …

Method For Target Detection In A High Noise Environment Through Frequency Analysis Using An Event-Based Vision Sensor, Will Johnston, Shannon Young, David Howe, Rachel Oliver, Zachary Theis, Brian Mcreynolds, Michael L. Dexter

Faculty Publications

Event-based vision sensors (EVSs), often referred to as neuromorphic cameras, operate by responding to changes in brightness on a pixel-by-pixel basis. In contrast, traditional framing cameras employ some fixed sampling interval where integrated intensity is read off the entire focal plane at once. Similar to traditional cameras, EVSs can suffer loss of sensitivity through scenes with high intensity and dynamic clutter, reducing the ability to see points of interest through traditional event processing means. This paper describes a method to reduce the negative impacts of these types of EVS clutter and enable more robust target detection through the use of …

Absence Of Phonon Softening Across A Charge Density Wave Transition Due To Quantum Fluctuations, Yubi Chen, Terawit Kongruengkit, Andrea Capa Salinas, Runqing Yang, Yujie Quan, Fanghao Zhang, Ganesh Pokharel, Linus Kautzsch, Stephen D. Wilson, Sai Mu

Faculty Publications

Kagome metals have emerged as a frontier in condensed matter physics due to their potential to host exotic quantum states. Among these, CsV₃Sb₅ has attracted significant attention for the unusual coexistence of charge density wave (CDW) order and unconventional superconductivity, presenting an ideal system for exploring the emergent phenomena from the interplay of phonons, electronic fluctuations, and topological effects. The nature of CDW formation in CsV3Sb5 is unconventional and has sparked considerable debate. In this study, we examine the origin of the CDW state via ab initio finite-temperature simulations of the lattice dynamics. Through a comparative study …

Volumetric Imaging Of Cellular Dynamics Using Light-Sheet Microscopy: From Subcellular Structures To Whole Organisms, Md Nasful Huda Prince

Optical Science and Engineering ETDs

Advancing biomedical imaging requires platforms that combine high-resolution, speed, and stability across biological scales. This dissertation presents three innovations designed to address limitations of conventional light-sheet and oblique plane imaging. First, we introduce Reflected Inline Detection in Epi-Oblique Plane Microscopy (RIDE-OPM), a compact and drift-resistant system that eliminates a tertiary detection path while maintaining alignment flexibility, enabling robust long-term live imaging. Second, we present a high-speed Axially Swept Light-Sheet Microscopy (ASLM) platform for cleared tissues, using dual foci and synchronized sweeping to achieve isotropic sub-micron resolution at up to 40 frames-per-second, a fourfold improvement over standard ASLM. Integrated with a …

An Alternative Approach To Non-Relativistic Quantum Mechanics In Curved Space, Robert A. Hulsey

Dissertations

In the research presented in this dissertation, we propose an alternative formulation of non-relativistic quantum mechanics in curved spaces (Riemannian manifolds). Some toy quantum models (2D quantum harmonic oscillator in Poincaré half-plane model and the flat chart model of hyperbolic 2-space) are studied to understand the physical implications of this alternative formulation.

Using Published Undergraduate Biomechanics Research On Hydra Mouth Opening To Train Undergraduates, Stephen Hackler, T. Goel, Jonah Pacis , '25, Eva-Maria S. Collins

Biology Faculty Works

Biophysics research is exciting because physical approaches to biology can provide novel insights, and it is challenging because it requires knowledge and skills from multiple disciplines. We have developed an undergraduate biophysics laboratory module that teaches fundamental skills such as time-lapse microscopy, image analysis, programming, critical reading of scientific literature, and basics of scientific writing and peer review. The module is accessible to students who are familiar with introductory statistics, cell biology, and differential calculus. We used published research on the biomechanics of Hydra mouth opening as a framework because it describes a stunning biological phenomenon: Hydra, a freshwater …

Measurements And First Principles Calculations On The Non-Centrosymmetric Superconductor Aupb3, Meena Shrestha

Dissertations

AuPb₃ is a non-centrosymmetric superconductor that crystallizes in a tetragonal structure and undergoes a superconducting transition at 4.4 K. Non-centrosymmetric superconductors that lack inversion symmetry are predicted to have an admixture of spinsinglet and spin-triplet symmetry induced by strong antisymmetric spin-orbit coupling (ASOC).

In this work, we investigated the normal and superconducting properties of AuPb₃. We also carried out the Density Functional Theory (DFT) calculations to study the strength of ASOC and its impact on vibrational and electronic properties. A high-quality polycrystalline sample of AuPb₃ was grown and characterized by powder x-ray diffraction, scanning electron microscopy, …

It’S A Lightboard … And A Glassboard!, Craig Looney

Physics Faculty Publications

In this poster I present an innovative lightboard-glassboard design concept and prototype. The device, when not in use as a lightboard, is positioned against a wall in a low-profile configuration and used as an illuminable office glassboard. For video production, the device – supported and guided by a robust anti-tip rail system – is safely rolled away from the wall and used as a lightboard. This device has several advantages over traditional mobile lightboard designs including ease and reliability of setup, elimination of storage and transport issues, usability in modest-sized offices, and functionality as an illuminable glassboard when not in …

Comparison Of Finite-Amplitude Acoustic Models: Single Equation Of Motion For Potential Vs System-Level Approaches, Mohammad Javad Mohaghegh Kojidi

LSU New Orleans Theses and Dissertations

This study evaluates two finite-amplitude acoustic models, by solving the associated equations of motion (in potential form), and then compares the results with recent studies using hyperbolic system-level approaches. An implicit numerical method is employed to solve the second-order equations in one dimension. The performances of the Diaz et al. (2018) and Blackstock (1963) models in approximating the acoustic special case of the Euler system, via velocity profile plots and related metrics, are evaluated and compared. Working in the setting of the classical signaling problem with sinusoidal input, present results (using the single equation of motion approach) provide independent confirmation …

Induced Helical Anisotropy In Permalloy Thin Films And Patterns, Md Mahmudul Hasan

LSU New Orleans Theses and Dissertations

The goal of this research was to create thin films with induced helical anisotropy and investigate magnetic properties of such films and their patterns. An alloy of 20% iron and 80% nickel (permalloy) was used because of very small magnetocrystalline anisotropy and magnetostriction. First, an unconventional method was used to deposit films with uniaxial anisotropy by sputtering the films onto silicon substrates in the presence of a uniform field of 50 Oe along the substrate plane. This resulted in magnetic atom pairs ordering along direction of the field during film growth. Shapes of hysteresis loops measured at different angles were …

Low Energy Ion Irradiation Effects In Electronic Devices And Materials, David C. Mccall

All Dissertations

The physics and engineering of ion-solid interactions are governed by the ion beam characteristics (flux, charge, energy) and target(s) in question. Here I present work on two projects related to the extraction of a high flux of low charge state Argon ions from a commercial plasma source and the irradiation of an engineered target, a transistor, with high charge state Argon ions.

An end-Hall ion source that produces a a high current plasma of ions and electrons in a rough vacuum environment is characterized. Using a Langmuir probe and multiple pressure measurements, the ion and electron content of the source …

Enhancing The Design Of Strained Superlattice Gallium Arsenide Based Photocathodes With Distributed Bragg Reflector, Adam D. A. Masters

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators play a crucial role in our understanding of matter and the universe and have numerous practical applications in various fields. These devices enable scientists to examine the smallest components of matter, study the forces that govern their interactions, and probe conditions from the early universe. Moreover, accelerators are valuable in medicine, industry, and research, enhancing imaging methods, cancer therapies, and manufacturing techniques. As the experiments conducted at these facilities evolve and require higher precision, improved particle sources must continue to advance to keep up with their requirements. To do that, we enhanced the design of spin polarized electron …

Flux Trapping Sensitivity On The Metallurgical State Of Superconducting Radio Frequency Niobium, Bashu Dev Khanal

Physics Theses & Dissertations

Trapped magnetic flux in superconducting radio-frequency (SRF) niobium cavities due to the incomplete Meissner effect is a significant source of rf losses. The relationship between flux expulsion and flux trapping sensitivity to the metallurgical state of 1.3 GHz and 3.0 GHz SRF niobium cavities fabricated from standard and cold-worked Nb sheets and subjected to various heat treatments has been studied. Flux expulsion increased with higher heat treatment temperature in all cavities. Nb cavities made from cold-worked sheets showed better flux expulsion after 800 ◦C/3 h compared to the standard SRF-grade Nb cavities. Similar flux expulsion was observed after annealing at …

Rabi Oscillations And Entanglement Between Two Atoms Interacting By The Rydberg Blockade And With A Quantized Radiation Field Studied By The Jaynes-Cummings Model, Francisco D. Santillan, Andreas Hanke

Physics & Astronomy Faculty Publications

The interaction between atoms and a quantized radiation field is fundamentally important in quantum optics and quantum information science. Due to their unusual properties, Rydberg atoms are promising building blocks for two-qubit gates and atom-light quantum interfaces, exploiting the Rydberg blockade interaction which prevents two atoms at close distance (< 10μm) from being simultaneously excited to Rydberg states. Recently, this effect was used to engineer quantum processors based on arrays of interacting Rydberg atoms illuminated by Raman lasers. Motivated by these experiments, we extend the Jaynes–Cummings model to study the interaction between two Rydberg atoms interacting by the Rydberg blockade and a quantized radiation field. We consider both number (Fock) states of the field and single-mode quantum coherent states. In particular, we discuss different types of entanglements between various components of the total system consisting of the two Rydberg-interacting atoms and coherent states of the field, and show that the behavior is significantly different compared to a system with non-interacting atoms corresponding to the two-atom Tavis-Cummings model. Our results are relevant in view of atom-light quantum interfaces as components for future long-distance quantum communication.

Dissipation Physics And Absorption Features In Black Hole X-Ray Binaries, Theodore Dezen Phd, Benjamin R. Cavallari

McNair Summer Research Program

As matter falls closer toward the center of the accretion disk it loses gravitational potential energy, part of which becomes radiation primarily in X-ray wavelengths. Accretion disk models often invoked to fit observed spectra predict relativistically smeared absorption features that are not present in data from black hole X-ray systems such as GX 339-4 and LMC-X3. Informed by recent local and global simulations, we conduct new disk structure and radiative transfer calculations with increased dissipation rates of gravitational potential energy into thermal energy in disk upper layers. We find a noticeable reduction of the absorption features compared to older models …

Guided Modes Through The Dual Perspectives Of Geometrical Optics And Wave Equation, Mason Spears

Mathematics and Statistics Undergraduate Departmental Honors Theses

In an optical waveguide, only finitely many electric field intensity profiles travel without loss, and these are aptly named guided modes. This paper uses fundamental concepts from the two paradigms of interpreting light, geometrical and physical optics, to derive guided modes axiomatically. First, basic principles of geometrical optics are demonstrated in a slab waveguide to explain characteristics of optical waveguides such as total internal reflection and numerical aperture. Dispersion curves are assembled from the same principles and used to show that only finitely many guided modes exist for a given waveguide. Next, Maxwell’s equations are used to derive the famous …

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Development Of A New Groundbased Instrumentation Technique For Low-Resolution Exoplanet Transmission Spectroscopy, Mary Anne Limbach, Luke M. Schmidt, Ryan J. Oelkers, Darren L. Depoy

Physics & Astronomy Faculty Publications

We present a new instrumentation technique for high-precision, ground-based spectrophotometric measurements ideal for low-resolution (R ∼ 20–60) exoplanet transmission spectroscopy. This technique employs novel thin-film coating technology for wide-band, simultaneous multi-band imaging, enabling high-precision differential photometry through self-referencing and comparison stars. Theoretical calculations and on-sky results show that this method effectively reduces 96% of amplitude scintillation noise and other systematics that typically limit ground-based spectrophotometric precision for bright stars. On-sky results are demonstrated using the custom-built Exoplanet Transmission Spectroscopy Imager (ETSI), deployed at the McDonald Observatory 2.1 m telescope in 2022. For a V = 9.7 mag star, ETSI …