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Articles 151 - 180 of 8852

Full-Text Articles in Physical Sciences and Mathematics

Hiding Behind A Curtain Of Dust: Gas And Dust Properties Of An Ultra-Luminous Strongly-Lensed Z = 3.75 Galaxy Behind The Milky Way Disc, Belén Alcalde Pampliega, Kevin C. Harrington, Aristeidis Amvrosiadis, Manuel Aravena, Min S. Yun, Hugo Messias, Antonio Hernán-Caballero, Leindert Boogaard, Axel Weiß, Benjamin Beauchesne, Alejandro Santamaría-Miranda, Monica Ivette Rodriguez, Eric Jiménez-Andrade, Manuel Solimano, James Lowenthal, Patrick Kamieneski, Q. Daniel Wang, Chentao Yang, Amit Vishwas, Pascale Hibon, Brenda Frye, Jorge González-Lopez, Yiqing Song, Meghana Killi Feb 2026

Hiding Behind A Curtain Of Dust: Gas And Dust Properties Of An Ultra-Luminous Strongly-Lensed Z = 3.75 Galaxy Behind The Milky Way Disc, Belén Alcalde Pampliega, Kevin C. Harrington, Aristeidis Amvrosiadis, Manuel Aravena, Min S. Yun, Hugo Messias, Antonio Hernán-Caballero, Leindert Boogaard, Axel Weiß, Benjamin Beauchesne, Alejandro Santamaría-Miranda, Monica Ivette Rodriguez, Eric Jiménez-Andrade, Manuel Solimano, James Lowenthal, Patrick Kamieneski, Q. Daniel Wang, Chentao Yang, Amit Vishwas, Pascale Hibon, Brenda Frye, Jorge González-Lopez, Yiqing Song, Meghana Killi

Astronomy: Faculty Publications

We present a detailed analysis of J154506, a strongly lensed submillimetre galaxy (SMG) behind the Lupus-I molecular cloud, and a characterisation of its physical properties using a combination of new and archival data, including VLT/MUSE and FORS2 optical data. We identify two high-significance (S/N >5) emission lines at 97.0 and 145.5 GHz, corresponding to CO(4-3) and CO(6-5), respectively, in spectral scans from the Atacama Compact Array (ACA) and the Large Millimetre Telescope (LMT), as well as the [CII] 158 µm fine-structure line at 400 GHz observed with the Atacama Pathfinder Experiment (APEX). These detections yield a spectroscopic redshift of …


A Solution To The Tension Of Burning On Neutron Stars And Nuclear Physics, Yuri Cavecchi, D. K. Galloway, A. Heger, P. Santillán-Ortega, M. Nava-Callejas, F. M. Vincentelli, Liliana E. Rivera Sandoval, A. Goodwin, Z. Johnston Feb 2026

A Solution To The Tension Of Burning On Neutron Stars And Nuclear Physics, Yuri Cavecchi, D. K. Galloway, A. Heger, P. Santillán-Ortega, M. Nava-Callejas, F. M. Vincentelli, Liliana E. Rivera Sandoval, A. Goodwin, Z. Johnston

Physics & Astronomy Faculty Publications

When neutron stars accrete matter from a companion star, this matter forms a disk around them and eventually falls on their surface. Here, the fuel can ignite into bright flashes called Type I bursts. Theoretical calculations based on state-of-the-art nuclear reactions are able to explain many features of the bursts. However, models predict that the bursts should cease at high accretion rates, whereas in many sources they disappear at much lower rates. Moreover, their recurrence times also show strong discrepancies with predictions. Although various solutions have been proposed, none can account for all the observational constraints. Here, we describe a …


Black Hole Spectroscopy And Tests Of General Relativity With Gw250114, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang Jan 2026

Black Hole Spectroscopy And Tests Of General Relativity With Gw250114, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang

Physics & Astronomy Faculty Publications

The binary black hole signal GW250114, the loudest gravitational wave detected to date, offers a unique opportunity to test Einstein’s general relativity (GR) in the high-velocity, strong-gravity regime and probe whether the remnant conforms to the Kerr metric. Upon perturbation, black holes emit a spectrum of damped sinusoids with specific, complex frequencies. Our analysis of the postmerger signal shows that at least two quasinormal modes are required to explain the data, with the most damped remaining statistically significant for about one cycle. We probe the remnant’s Kerr nature by constraining the spectroscopic pattern of the dominant quadrupolar (ℓ =𝑚 =2) …


A Transferable Force Field For Simulating Adsorption In Metal–Organic Frameworks With Open Metal Sites Based On The 12–6–4 Lennard-Jones Potential, Meng Du, Alan Rodriguez, Matthew Z. Lin, Haoyuan Chen Jan 2026

A Transferable Force Field For Simulating Adsorption In Metal–Organic Frameworks With Open Metal Sites Based On The 12–6–4 Lennard-Jones Potential, Meng Du, Alan Rodriguez, Matthew Z. Lin, Haoyuan Chen

Physics & Astronomy Faculty Publications

Metal–organic frameworks (MOFs) that contain coordinatively unsaturated open metal sites (OMSs) provide strong host–guest interactions, making them promising sorbents for low-concentration gas adsorption applications such as direct air capture and atmospheric water harvesting. However, accurately modeling host–guest interactions involving OMSs remains challenging for classical force fields (FFs) based on the 12–6 Lennard–Jones (LJ) potential, as the polarization effect of the guest molecule induced by the positively charged OMS is not considered. Here, we introduce an FF based on the 12–6–4 LJ potential, which incorporates charge–induced dipole interactions and is parametrized against a diverse set of host–guest potential energy surfaces (PESs) …


Crystal Structures, Optical Behavior, And Magnetic Properties In Hydrated Lanthanide Iron Sulfates, Chole Jones, Silu Huang, Tyler L. Spano, Eric A. Gabilondo, Mohammed Al-Fahdi, Kara Trim, Mary Douglas, Rongying Jin, Andrew Miskowiec, P. Shiv Halasyamani, Ming Hu, Jie Ling Jan 2026

Crystal Structures, Optical Behavior, And Magnetic Properties In Hydrated Lanthanide Iron Sulfates, Chole Jones, Silu Huang, Tyler L. Spano, Eric A. Gabilondo, Mohammed Al-Fahdi, Kara Trim, Mary Douglas, Rongying Jin, Andrew Miskowiec, P. Shiv Halasyamani, Ming Hu, Jie Ling

Faculty Publications

Single crystals of LnFe(SO4)3(H2O)2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm; compounds 1–11) and LnFe(SO4)3(H2O) (Ln = Tm, Yb, Lu; compounds 12–14) were synthesized under hydrothermal conditions. Single-crystal X-ray diffraction (SCXRD) analysis revealed that the dihydrated compounds (1–11) crystallize in centrosymmetric (CS) structures, with the lanthanide ions adopting eight-coordinate geometries. In contrast, the monohydrated compounds (12–14) exhibit noncentrosymmetric (NCS) structures, where the lanthanide ions are seven-coordinated. Vibrating sample magnetometry (VSM) confirmed that compounds 2, …


Gatos – Xi. Excess Dust Heating In The Narrow-Line Regions Of Nearby Agn Revealed With Jwst/Miri, Houda Haidar, David J. Rosario, Ismael García-Bernete, Almudena Alonso-Herrero, Anelise Audibert, Steph Campbell, Chris M. Harrison, Tiago Costa, Laura Hermosa Muñoz, Françoise Combes, Dimitra Rigopoulou, Claudio Ricci, Cristina Ramos Almeida, Enrica Bellocchi, Peter Boorman, Andrew Bunker, Richard Davies, Daniel Delaney, Tanio Díaz Santos, Federico Esposito, Enrique Lopez Rodriguez, Et. Al. Jan 2026

Gatos – Xi. Excess Dust Heating In The Narrow-Line Regions Of Nearby Agn Revealed With Jwst/Miri, Houda Haidar, David J. Rosario, Ismael García-Bernete, Almudena Alonso-Herrero, Anelise Audibert, Steph Campbell, Chris M. Harrison, Tiago Costa, Laura Hermosa Muñoz, Françoise Combes, Dimitra Rigopoulou, Claudio Ricci, Cristina Ramos Almeida, Enrica Bellocchi, Peter Boorman, Andrew Bunker, Richard Davies, Daniel Delaney, Tanio Díaz Santos, Federico Esposito, Enrique Lopez Rodriguez, Et. Al.

Faculty Publications

We present James Webb Space Telescope/Mid-Infrared Instrument imaging of eight nearby active galactic nuclei (AGN) from the GATOS (Galactic Activity, Torus, and Outflow Survey) survey to investigate the physical conditions of extended dust in their narrow-line regions (NLRs). In four galaxies (ESO 428–G14, NGC 4388, NGC 3081, and NGC 5728), we detect spatially resolved dust structures extending ∼100–200 pc along the NLR. In these systems, we find a strong link between the morphology of the dust, the radio ejecta, and the coronal [Si VI] emission, implying that dust carries imprints of the processes shaping the NLR. Using spatially resolved …


First Results On The Search For Lepton Number Violating Neutrinoless Double-Β Decay With The Legend-200 Experiment, H. Acharya, N. Ackermann, M. Agostini, A. Alexander, C. Andreoiu, G. R. Araujo, Frank Avignone Iii, M. Babicz, W. Bae, A. M. Bakalyarov, M. Balata, A. S. Barabash, C. J. Barton, L. Baudis, C. Bauer, E. Bernieri, L. Bezrukov, K. H. Bhimani, V. Biancaccu, E. Blalock, Et. Al. Jan 2026

First Results On The Search For Lepton Number Violating Neutrinoless Double-Β Decay With The Legend-200 Experiment, H. Acharya, N. Ackermann, M. Agostini, A. Alexander, C. Andreoiu, G. R. Araujo, Frank Avignone Iii, M. Babicz, W. Bae, A. M. Bakalyarov, M. Balata, A. S. Barabash, C. J. Barton, L. Baudis, C. Bauer, E. Bernieri, L. Bezrukov, K. H. Bhimani, V. Biancaccu, E. Blalock, Et. Al.

Faculty Publications

The LEGEND Collaboration is searching for neutrinoless double-beta (0νββ) decay by operating high-purity germanium detectors enriched in 76Ge in a low-background liquid argon environment. Building on key technological innovations from the GERmanium Detector Array (GERDA) experiment and the MAJORANA DEMONSTRATOR experiment, LEGEND-200 has performed a first 0νββ decay search based on 61.0 kg yr of data. Over half of this exposure comes from our highest performing detectors, including newly developed inverted-coaxial detectors, and is characterized by an estimated background level of 0.5+0.3−0.2 cts/(keV ton yr) in the 0νββ decay signal region. A combined …


Spectroscopic Investigations On Polyvinylidene Fluoride Nanofibers, Parinaz Amaniabdolmalaki, Jui Vitthal Kharade, Alexandro Trevino, Lydia Morales, Karen Lozano, Victoria Padilla, Karen S. Martirosyan, Horacio Vasquez, Mircea Chipara Jan 2026

Spectroscopic Investigations On Polyvinylidene Fluoride Nanofibers, Parinaz Amaniabdolmalaki, Jui Vitthal Kharade, Alexandro Trevino, Lydia Morales, Karen Lozano, Victoria Padilla, Karen S. Martirosyan, Horacio Vasquez, Mircea Chipara

Physics & Astronomy Faculty Publications

The production of polyvinylidene fluoride nanofibers by force-spinning from polymer solutions was confirmed by electron microscopy. The structural and phase characteristics of the resulting nanofiber mats were examined using Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance mode, Raman spectroscopy, and X-ray Diffraction. Results from all these techniques consistently indicated that both the powder and the mats of polyvinylidene fluoride predominantly contain the α phase, with a small admixture of the β phase. Within experimental errors, no other phases were noticed both in the powder and in the as-obtained mats. The ratios of the areas of the Raman lines at …


Jwst Interferometric Imaging Reveals The Dusty Torus Obscuring The Supermassive Black Hole Of Circinus Galaxy, Enrique Lopez Rodriguez, Joel Sanchez-Bermudez, Omaira González-Martín, Robert Nikutta, Ryan M. Lau, Deepashri Thatte, Julien H. Girard, Ismael García-Bernete, Matthew J. Hankins Jan 2026

Jwst Interferometric Imaging Reveals The Dusty Torus Obscuring The Supermassive Black Hole Of Circinus Galaxy, Enrique Lopez Rodriguez, Joel Sanchez-Bermudez, Omaira González-Martín, Robert Nikutta, Ryan M. Lau, Deepashri Thatte, Julien H. Girard, Ismael García-Bernete, Matthew J. Hankins

Faculty Publications

The dusty and molecular torus is an elusive structure surrounding supermassive black holes, yet its importance is unequivocal for understanding feedback and accretion mechanisms. The torus and accretion disk feed the inspiraling gas onto the active nucleus, launching outflows that fundamentally connect the active nucleus’s activity to the host galaxy. In this work, we utilize the aperture-masking interferometric mode onboard the JWST to achieve a resolution of 0.08" at 4.3 μm and bring out the fainter features in the central 10 pc of the Circinus galaxy. We show that most of the dust mass is located along the equatorial …


Contact Binary Stars: A Roadmap To Their Nature And Evolution, Larry A. Molnar, M. Chalov, R. Deaton, R. Reynolds Jan 2026

Contact Binary Stars: A Roadmap To Their Nature And Evolution, Larry A. Molnar, M. Chalov, R. Deaton, R. Reynolds

University Faculty Publications and Creative Works

A complete life cycle for W UMa systems

  • Mass transfer from secondary driven by primary
  • Sign of flow essential to stability criteria 
  • Consistent with observations of distributions of M, T, P, q, dP/dt, (P,q)merger

Ongoing

  • THEORY 
  • Understand f distribution 
  • Compute grid of models to compare with populations of various ages • 

OBSERVATION:Rubin observatory data

  • Establish parameter distributions vs. location or kinematics 
  • Find the next red nova before it explodes


Measurement Of 18f(Alpha,P)21ne With The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Keilah S. Davis Jan 2026

Measurement Of 18f(Alpha,P)21ne With The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Keilah S. Davis

LSU Doctoral Dissertations

Certain (α,p) reactions on proton-rich nuclei are among the most important nuclear reactions occurring during Type I X-ray bursts, as well as being impactful in stellar explosions during the Asymptotic Giant Branch (AGB) phase and on accreting white dwarfs (WD). However, large uncertainties remain for reaction rates on some radioactive nuclei due to the lack of direct measurements. The Array for Nuclear Astrophysics and Structure with Exotic Nuclei (ANASEN) is a gas target and charged-particle detector designed for direct measurements of (α,p) reactions. ANASEN was redesigned with two hexagonal barrels of 100-µm-thick silicon strip surrounding the beam axis over a …


Infinite Line, Infinite Knowledge: The 'Spera' And Organized Chaos In Lambert's Encyclopedia, The 'Liber Floridus', Ava Romano Jan 2026

Infinite Line, Infinite Knowledge: The 'Spera' And Organized Chaos In Lambert's Encyclopedia, The 'Liber Floridus', Ava Romano

Theses and Dissertations

The Liber Floridus is a medieval encyclopedia renowned for its program of circular diagrams, or sperae. Inside this manuscript of 190 chapters, these diagrams frame and embody written knowledge, revealing a connection between encyclopedism and life in the Benedictine monastery by creating a coherent visual organization of chapters.


A Comparison Of Time-Dependent Cloudy Astrophysical Code Simulations With Experimental X-Ray Spectra From Kev Laser-Generated Argon Plasmas, N. Rathee, F. P. Keenan, R. J. R. Williams, Gary Ferland, S. J. Rose, S. White, D. Riley Jan 2026

A Comparison Of Time-Dependent Cloudy Astrophysical Code Simulations With Experimental X-Ray Spectra From Kev Laser-Generated Argon Plasmas, N. Rathee, F. P. Keenan, R. J. R. Williams, Gary Ferland, S. J. Rose, S. White, D. Riley

Physics and Astronomy Faculty Publications

We have generated strongly photoionized Ar plasmas in experiments designed to use primarily X-ray l-shell line emission generated from Ag foils irradiated by the VULCAN high-power laser at the UK Central Laser Facility. The principle of the experiment is that use of line emission rather than the usual sub-keV quasi-blackbody source allows keV radiation to play a more dominant role compared to softer X-rays and thus mimic the effect of a blackbody with a higher effective spectral temperature. Our aim is to reproduce in the laboratory the extreme photoionization conditions found in accretion-powered astrophysical sources. In this paper, we compare …


A Flux-Limited Sample Of Dusty Star-Forming Galaxies From The Atacama Cosmology Telescope: Physical Properties And The Case For Multiplicity, K. R. Hall, J. B. Hassan, R. M. Feder, T. A. Marriage, M. Zemcov, Jesus Rivera Jan 2026

A Flux-Limited Sample Of Dusty Star-Forming Galaxies From The Atacama Cosmology Telescope: Physical Properties And The Case For Multiplicity, K. R. Hall, J. B. Hassan, R. M. Feder, T. A. Marriage, M. Zemcov, Jesus Rivera

Physics & Astronomy Faculty Works

No abstract provided.


Universe Without A Cause: A Reply To David Lu, Daniel Linford Jan 2026

Universe Without A Cause: A Reply To David Lu, Daniel Linford

Philosophy Faculty Publications

David Lu has recently argued that denying the Modified Causal Principle (MCP)—that if the universe began to exist, then it has a cause—leads to the conclusion that we likely inhabit an Omphalos universe, one that began recently with the appearance of age. Lu goes on to argue that if the universe is likely Omphalos, then independent measurements of the universe’s age are unlikely to agree. I offer three families of objections. First, Lu’s probabilistic reasoning faces technical challenges and, even if those challenges are overcome, cannot rule out an Omphalos universe. Second, I propose an alternative hypothesis that does so. …


Accelerator Based Fusion Reactor With Magnetic Mirror, Keh-Fei Liu Jan 2026

Accelerator Based Fusion Reactor With Magnetic Mirror, Keh-Fei Liu

Physics and Astronomy Faculty Publications

We consider an implementation of the novel accelerator-based fusion reactor scheme using a setup in which ion and electron beams are injected into the end openings of an axisymmetric magnetic mirror. While the magnetic mirror ensures transverse confinement of the plasma, the injected beams contribute to axial confinement, thereby extending the overall plasma lifetime. The ion beam energy is initially set above the resonance region of the fusion reactions, allowing fusion to occur both via resonance and thermal mechanisms as the beam slows down to the plasma temperature. Beam energy loss (stopping power) contributes to plasma heating, offsetting radiative losses …


Dynamical Phases Of Higher Dimensional Floquet Cfts, Diptarka Das, Sumit R. Das, Arnab Kundu, Krishnendu Sengupta Jan 2026

Dynamical Phases Of Higher Dimensional Floquet Cfts, Diptarka Das, Sumit R. Das, Arnab Kundu, Krishnendu Sengupta

Physics and Astronomy Faculty Publications

This paper investigates the dynamical phases of Floquet Conformal Field Theories (CFTs) in space-time dimensions greater than two. Building upon our previous work which introduced quaternionic representations for studying Floquet dynamics in higher-dimensional CFTs, we now explore more general square pulse drive protocols that go beyond a single SU(1,1) subgroup. We demonstrate that, for multi-step drive protocols, the system exhibits distinct dynamical phases characterized by the nature of the eigenvalues of the quaternionic matrix representing time evolution in a single cycle, leading to different stroboscopic responses. Our analysis establishes a fundamental geometric interpretation where these dynamical phases directly correspond to …


Emission-Line Diagnostics At Z ≳ 2: A Probe Of The Ionizing Spectrum And Α-Enhancement Beyond Cosmic Noon, Leonardo Clarke, Natalie Lam, Alice E. Shapley, Michael W. Topping, Gabriel B. Brammer, Ryan L. Sanders, Naveen Reddy, Shreya Karthikeyan Jan 2026

Emission-Line Diagnostics At Z ≳ 2: A Probe Of The Ionizing Spectrum And Α-Enhancement Beyond Cosmic Noon, Leonardo Clarke, Natalie Lam, Alice E. Shapley, Michael W. Topping, Gabriel B. Brammer, Ryan L. Sanders, Naveen Reddy, Shreya Karthikeyan

Physics and Astronomy Faculty Publications

We analyze several key rest-optical emission-line ratios in a sample of 828 galaxies as well as composite spectra from JADES DR3 in the range 1.4 <  z <  7. These emission-line ratios include: [O iii]λ5008/Hβ, [N ii]λ6585/Hα, [S ii]λλ6718, 6733/Hα, [O i]λ6302/Hα, O32, R23, Ne3O2, and RO2Ne3. We find evidence for a harder ionizing spectrum at z ∼ 3.5 compared to z ∼ 2 at fixed gas-phase metallicity, resulting in a pronounced shift in the star-forming galaxy locus on the [N ii]/Hα Baldwin-Phillips-Terlevich (BPT) diagram and the O32 versus R23 diagram. At …


The Link Fantastic: Detecting And Linking Simulated, Nongravitationally-Accelerating Objects With The Rubin Observatory Pipeline, Ellie White Jan 2026

The Link Fantastic: Detecting And Linking Simulated, Nongravitationally-Accelerating Objects With The Rubin Observatory Pipeline, Ellie White

Theses, Dissertations and Capstones

Rubin Observatory’s Legacy Survey of Space and Time (LSST) is poised to revolutionize our understanding of the Solar System. After only a few months of regular operations, Rubin has already discovered over 11,000 new Solar System bodies, and is projected to discover millions more. With discoveries pouring in, and with the development of moving object detection pipelines for routine observing, one key question is: how effectively can Rubin detect and identify objects with anomalous trajectories? The answer is of interest not only for natural bodies in our Solar System, but also in the search for technosignatures, which could be identified …


Gpu And Pso Accelerated Low-Latency Fully-Coherent All-Sky Search For Compact Binary Coalescences, Soumya D. Mohanty Jan 2026

Gpu And Pso Accelerated Low-Latency Fully-Coherent All-Sky Search For Compact Binary Coalescences, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

The fully-coherent all-sky (FCAS) search, which combines data from a gravitational wave detector network into a single likelihood function, is the preferred method prescribed by statistical theory for Gaussian noise. However, so far, its exorbitant computational cost has blocked its use for compact binary coalescence searches. We introduce a solution combining Particle Swarm Optimization with Graphics Processing Unit (GPU) acceleration that is ≈ 50-fold faster than real-time analysis. This transforms the prospect of a low-latency FCAS search on all GW data into a practical reality for the first time. With large-scale simulations enabled by this speedup, we examine the issue …


Gauge-Invariant Gravitational Wave Polarization In Metric F(R) Gravity With Cosmological Implications, Ramesh Radhakrishnan, David Mcnutt, Delaram Mirfendereski, Alejandro Pinero, Eric Davis, William Julius, Gerald Cleaver Jan 2026

Gauge-Invariant Gravitational Wave Polarization In Metric F(R) Gravity With Cosmological Implications, Ramesh Radhakrishnan, David Mcnutt, Delaram Mirfendereski, Alejandro Pinero, Eric Davis, William Julius, Gerald Cleaver

Physics & Astronomy Faculty Publications

We develop a fully gauge-invariant analysis of gravitational-wave polarizations in metric 𝑓⁡(𝑅) gravity with a particular focus on the modified Starobinsky model 𝑓⁡(𝑅) =𝑅 +𝛼⁢𝑅2 −2⁢Λ, whose constant-curvature solution 𝑅𝑑 =4⁢Λ provides a natural de Sitter background for both early- and late-time cosmology. Linearizing the field equations around this background, we derive the Klein–Gordon equation for the curvature perturbation 𝛿⁢𝑅 and show that the scalar propagating mode acquires a mass 𝑚2𝜓 =1/(6⁢𝛼), highlighting how the same scalar degree of freedom governs inflationary dynamics at high curvature and the propagation of gravitational waves in the current accelerating Universe. Using the scalar–vector–tensor …


Mathematicly Rigorous Quantum General Relativity, I: Pure, James Glimm Jan 2026

Mathematicly Rigorous Quantum General Relativity, I: Pure, James Glimm

Department of Applied Mathematics & Statistics Faculty Publications

A pure quantum general relativity field is one lacking in matter. Such a field has a Lorentzian space-time geometry. A renormalized perturbation expansion, truncated to all finite orders, establishes  the existence of pure quantum general relativity with full mathematical rigor


Discovery Of Tidal Disruption Event Candidates In The Hubble Catalog Of Variables, Elliot M. Schweitzer Jan 2026

Discovery Of Tidal Disruption Event Candidates In The Hubble Catalog Of Variables, Elliot M. Schweitzer

Pitzer Senior Theses

A tidal disruption event (TDE) occurs when a star passes within the tidal radius of the supermassive black hole (SMBH) likely to reside at the center of most galaxies. Within this radius, the star is torn apart as tidal forces overcome the star's binding energy, and roughly half of the stellar debris spirals back towards the SMBH. The formation of an accretion disk produces bright emissions for months to years, modeled to peak in the ultraviolet and extend well into x-ray and optical wavelengths. TDEs occur only about once every 104-105 years per galaxy. As one of …


Uncertainty Quantification, Propagation & Conjunction Assessment In Orbital Mechanics Using Generalized Polynomial Chaos Expansion & 2-Dimensional Conjunction Plane Analysis Techniques, Monalisa Karim Jan 2026

Uncertainty Quantification, Propagation & Conjunction Assessment In Orbital Mechanics Using Generalized Polynomial Chaos Expansion & 2-Dimensional Conjunction Plane Analysis Techniques, Monalisa Karim

Mechanical and Aerospace Engineering Theses

Uncertainties, that are inherent to dynamic models, can be associated with state initial conditions, force modelling errors, navigation and actuation errors. In system modelling stochastic differential equations are used to represent dynamic phenomena with uncertainties, for which the solutions are probability density functions of quantities of interest characterizing the realization of the stochastic processes. In Polynomial Chaos Expansion (PCE) propagation, these solutions are represented as weighted sums of multivariate spectral polynomials that are functions of the input random variables. Generalized polynomial chaos expansion (gPC) is an extension to the original homogenous PCE which projects the random solution onto a basis …


A Chandra View Of Spt-Cl J0217–5014: A Massive Galaxy Cluster At A Cosmic Intersection At Z = 0.53, Dan Hu, Shida Fan, Zhongsheng Yuan, Junjie Mao, Norbert Werner, Yuanyuan Su, François Mernier, Yuanyuan Zhao, Liyi Gu, Haiguang Xu Jan 2026

A Chandra View Of Spt-Cl J0217–5014: A Massive Galaxy Cluster At A Cosmic Intersection At Z = 0.53, Dan Hu, Shida Fan, Zhongsheng Yuan, Junjie Mao, Norbert Werner, Yuanyuan Su, François Mernier, Yuanyuan Zhao, Liyi Gu, Haiguang Xu

Physics and Astronomy Faculty Publications

Context. Galaxy clusters trace the densest regions of the cosmic web and are crucial laboratories for studying the thermodynamic and chemical evolution of the intracluster medium (ICM). The massive galaxy cluster SPT-CL J0217−5014 (z ∼ 0.53; M500 ∼ 3 × 1014 M) is one of the Swift X-Ray Telescope serendipitous galaxy clusters with the highest reported Fe abundance (∼1.3 ± 0.4 Z within ∼ 1.7) and a potentially disturbed morphology.

Aims. SPT-CL J0217−5014 presents an intriguing opportunity to investigate ICM chemical enrichment and cool-core survival. With this study, we aim to …


A Uniform Analysis Of Gas-Phase Metallicity Evolution With 1–3 Gyr Time Sampling Over The Past 12 Gyr, Shweta Jain, Ryan L. Sanders, Ali Ahmad Khostova, Tucker Jones, Alice E. Shapley, Naveen Reddy, Alex M. Garcia, Paul Torrey, Alison L. Coil Jan 2026

A Uniform Analysis Of Gas-Phase Metallicity Evolution With 1–3 Gyr Time Sampling Over The Past 12 Gyr, Shweta Jain, Ryan L. Sanders, Ali Ahmad Khostova, Tucker Jones, Alice E. Shapley, Naveen Reddy, Alex M. Garcia, Paul Torrey, Alison L. Coil

Physics and Astronomy Faculty Publications

We present a systematic investigation of the evolution of the mass–metallicity relation (MZR) and fundamental metallicity relation (FMR) using uniform metallicity diagnostics across redshifts z ∼ 0 to z ∼ 3.3. We present new Keck/Deep Imaging Multi-Object Spectrograph measurements of the [O II]λλ3726, 3729 emission line doublet for star-forming galaxies at z ∼ 1.5 with existing measurements of redder rest-optical lines from the MOSFIRE Deep Evolution Field survey. These new observations enable uniform estimation of the gas-phase oxygen abundance using ratios of the [O II], Hβ, and [O III] lines for mass-binned samples of star-forming galaxies …


Energy Levels Of Multiscale Bound States From Qed Energy-Momentum Trace, Michael I. Eides, Vladimir A. Yerokhin Jan 2026

Energy Levels Of Multiscale Bound States From Qed Energy-Momentum Trace, Michael I. Eides, Vladimir A. Yerokhin

Physics and Astronomy Faculty Publications

Energy levels of quantum electrodynamics (QED) bound states, which depend on a number of independent mass parameters, can be calculated as matrix elements of the QED energy-momentum tensor trace. As an example of such system we consider muonic hydrogen. The leading one-loop corrections to its energy levels depend on the electron and muon masses. These corrections are calculated as matrix elements of the energy-momentum tensor trace. Respective one-loop trace diagrams are different from the standard Lamb shift diagrams. We explain analytically and diagrammatically why two different sets of diagrams lead to the same results. Similar relationships should also hold beyond …


Fe Xviii–Xxiv Kβ Inner-Shell Absorption Lines In The X-Ray Spectra Of Neutron Star And Black Hole Binaries With Xrism, Masahiro Tsujimoto, Daiki Miura, Hiroya Yamaguchi, Ehud Behar, Chris Done, María Díaz Trigo, Chamani M. Gunasekera, Peter A. M. Van Hoof, Stefano Bianchi, Maryam Dehghanian, Gary J. Ferland Jan 2026

Fe Xviii–Xxiv Kβ Inner-Shell Absorption Lines In The X-Ray Spectra Of Neutron Star And Black Hole Binaries With Xrism, Masahiro Tsujimoto, Daiki Miura, Hiroya Yamaguchi, Ehud Behar, Chris Done, María Díaz Trigo, Chamani M. Gunasekera, Peter A. M. Van Hoof, Stefano Bianchi, Maryam Dehghanian, Gary J. Ferland

Physics and Astronomy Faculty Publications

The advent of the X-ray microcalorimeter spectrometer Resolve onboard the XRISM space telescope opened a new era for high-resolution X-ray spectroscopy of astrophysical plasmas. Many spectral features were newly detected, including the Kα and Kβ inner-shell transition lines of mildly ionized (F- to Li-like) Fe at 6–8 keV in the spectra of X-ray binaries and active galactic nuclei. The widely used atomic databases contain information on the Kα but not Kβ lines of these ions. We conducted the atomic structure calculation using FAC to derive the Fe Kα and Kβ lines and verified the …


Efficient Search For Detection Candidates Using A Peak Finder Strategy For All-Sky-All-Frequency Gravitational Wave Radiometer, Arindam Sharma, Deepali Agarwal, Sanjit Mitra Jan 2026

Efficient Search For Detection Candidates Using A Peak Finder Strategy For All-Sky-All-Frequency Gravitational Wave Radiometer, Arindam Sharma, Deepali Agarwal, Sanjit Mitra

Physics & Astronomy Faculty Publications

The first all-sky-all-frequency (ASAF) radiometer search was conducted using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. The significance of this search lies in its fast and unmodeled approach, leveraging a cross-correlation technique to identify common signals across the detector network. As a result, this method serves as an excellent alternative to search for unknown or poorly modeled continuous wave sources and narrow band components of the gravitational wave (GW) background. For continuous wave sources whose waveform can be modeled, this method can serve as the first stage of a hierarchical scheme by …


Active Galactic Nuclei Across Scales: From Blazar Jets To Dark Matter Halos, Stephanie Ann Podjed Jan 2026

Active Galactic Nuclei Across Scales: From Blazar Jets To Dark Matter Halos, Stephanie Ann Podjed

Dartmouth College Ph.D Dissertations

Within ΛCDM, galaxies form and evolve within dark matter halos, with both central and satellite galaxies contributing to the total stellar mass content. Virtually every massive galaxy harbors a supermassive black hole (SMBH) at its center, with a small fraction of the population growing by actively accreting material; we call this an active galactic nucleus (AGN). The processes giving rise to an AGN phase (i.e., growth of a SMBH) releases enormous amounts of energy in the form of radiation, outflows, and relativistic jets that are able to significantly affect the formation and evolution of galaxies. Blazars are an extreme class …