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Articles 1 - 30 of 479

Full-Text Articles in Physics

Table Of Contents May 2026

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler Apr 2026

Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler

Faculty Publications

We apply Bayesian inference to the order-by-order chiral perturbation theory (χPT) expansions for the axial-vector coupling constant gA and the nucleon mass mN, and thereby infer the scales at which χPT breaks down for these two observables. Using a pointwise Bayesian analysis, we find that the inferred breakdown scales are notably different for the two observables. For the chiral expansion of gA, we obtain 251+20−50 MeV and 211+20−30 MeV using two distinct sets of low-energy constants, while for the chiral expansion of mN we infer a significantly …


First-Order Axial Perturbation Of The Reissner–Nordström Metric Against A Possible Parity-Violating Gravity Background, Abhishek Rout, Brett David Altschul Mar 2026

First-Order Axial Perturbation Of The Reissner–Nordström Metric Against A Possible Parity-Violating Gravity Background, Abhishek Rout, Brett David Altschul

Faculty Publications

We study axial perturbations of Reissner–Nordström black holes within the general frame-work of parity-violating modified gravity theories. We derive the governing equations for a class of frame-dragging perturbations, focusing on the symmetry structure and radial dependence of the perturbed metric component, describing its behavior across three distinct regions: near the singularity (r → 0), between the inner and outer Reissner–Nordström horizons (r− < r < r+), and in the asymptotic exterior regime (r → ∞). Using a combination of analytical and numerical methods, we analyze the solutions for varying black hole charge-to-mass ratios (Q/M) and angular momentum parameters (l). Key findings include the suppression of perturbations by the electromagnetic field for higher Q/M; the emergence of radial resonance-like behavior for specific l values; and a high degree of symmetry for solutions in the extremal limit (Q/M ∼ 1), attributed to the AdS2 × S 2 near-horizon geometry. The WKB approximation is employed to study the high-l regime, revealing quantized radial resonance modes and singular behavior in the extremal limit. Additionally, we explore the role of boundary conditions and the possibility of a Chern–Simons field Θ as the source of the parity violation, showing that consistency and the behavior of the perturbations under time reversal demand a constant field (and thus no actually observable Chern–Simons effects) at leading order. These results provide a basis for further analysis of the stability and dynamical properties of charged black holes in parity-violating theories, with potential experimental signatures in gravitational wave observations.


New Avenues For |Δb=2| Processes Beyond Neutron-Antineutron Oscillations, Arnau Basi Beneito, Svjetlana Fajfer, Alexey A. Petrov Mar 2026

New Avenues For |Δb=2| Processes Beyond Neutron-Antineutron Oscillations, Arnau Basi Beneito, Svjetlana Fajfer, Alexey A. Petrov

Faculty Publications

We explore baryon-number-violating (|∆B| = 2) processes beyond the well-known neutron-antineutron (n-n̄) oscillations, focusing on the Λ-Λ̄ system. The presence of a strange quark in the Λ baryon introduces a new set of six-quark operators roughly of the form (uds)2, which are different from the (udd)2 operators responsible for n-n̄ oscillations. Using the Standard Model Effective Field Theory (SMEFT), we classify all dimension-9 operators that cause |∆B| = 2  transitions and study their UV completions mediated by exotic scalar fields with trilinear interactions. We demonstrate that …


Complex Spin Structure In Co-Trimer-Chain Li2Co3Se4O12, Jie Xing, Feng Ye, Daniel Duong, Sai Mu, Max T. Pan, Rongying Jin Mar 2026

Complex Spin Structure In Co-Trimer-Chain Li2Co3Se4O12, Jie Xing, Feng Ye, Daniel Duong, Sai Mu, Max T. Pan, Rongying Jin

Faculty Publications

Complex magnetic materials are extremely attractive for revealing unconventional spin states and novel magnetic excitations. Here, we report the structural, thermodynamic, and magnetic properties of a novel magnetic material Li2Co3Se4O12based on x-ray and neutron diffraction, specific heat, magnetization, and x-ray photoelectron spectroscopy measurements. X-ray and neutron diffraction refinements reveal two Co sites Co (1) and Co (2) even though both are in the octahedral environment. While they are not connected along the b and c directions, these octahedra are edge-shared forming the Co (2) – Co (1) – Co (2) trimer chain …


Egain Tube Memristors Offering Reliable Switching On A Biological Time Scale, Yuriy V. Pershin, Liya Patel, Bapi Bera, Doug Aaron, Stephen A. Sarles Feb 2026

Egain Tube Memristors Offering Reliable Switching On A Biological Time Scale, Yuriy V. Pershin, Liya Patel, Bapi Bera, Doug Aaron, Stephen A. Sarles

Faculty Publications

Memristive devices have been considered promising candidates for nature-inspired computing and in-memory information processing. However, experimental devices developed to date typically show significant variability and function at different time scales than biological neurons and synapses. This study presents a memristive device comprised of liquid-metal eutectic gallium indium (EGaIn) contained within a mm-scale tube that operates via a bulk, voltage-dependent switching mechanism and exhibits distinct unipolar resistive switching characteristics that occur on a biological time scale (tens of milliseconds). The switching mechanism involves voltage-controlled growth and dissolution of an oxide layer on the surface of the liquid metal in contact with …


The Detection Of Marine Microseismic Activity With The Cuore Tonne-Scale Cryogenic Experiment, D. Q. Adams, C. Aldunio, K. Alfonso, A. Armatol, Frank Avignone Iii, O. Azzolini, G. Bari, F. Bellini, G. Benato, M. Beretta, C. Bucci, J. Camilleri, A. Caminata, A. Campani, J. Cao, C. Capelli, S. Capelli, L. Capelli, J. Capelli, A. Caminata, Et. Al. Feb 2026

The Detection Of Marine Microseismic Activity With The Cuore Tonne-Scale Cryogenic Experiment, D. Q. Adams, C. Aldunio, K. Alfonso, A. Armatol, Frank Avignone Iii, O. Azzolini, G. Bari, F. Bellini, G. Benato, M. Beretta, C. Bucci, J. Camilleri, A. Caminata, A. Campani, J. Cao, C. Capelli, S. Capelli, L. Capelli, J. Capelli, A. Caminata, Et. Al.

Faculty Publications

Vibrations from experimental setups and the environment are a persistent source of noise for low-temperature calorimeters searching for rare events, including neutrinoless double beta (0νββ) decay or dark matter interactions. Such noise can significantly limit experimental sensitivity to the physics case under investigation. Here, we report the detection of marine microseismic vibrations using mK-scale calorimeters. This study employs a multi-device analysis correlating data from CUORE, the leading experiment in the search for 0νββ decay with mK-scale calorimeters, and the Copernicus Earth Observation program, revealing the seasonal impact of Mediterranean Sea activity on CUORE’s …


A New Highly Oxygen-Deficient And Cubic Pr3Zro8-Δ For Intermediate-Temperature Thermochemical Production Of Oxygen And Hydrogen, Jiaxin Lu, Yongliang Zhang, Luhong Chen, Yan Chen, Ke An, Yasser Shoukry, Xinfang Jin, Zhi-Hao Wang, Sai Mu, Kevin Huang Feb 2026

A New Highly Oxygen-Deficient And Cubic Pr3Zro8-Δ For Intermediate-Temperature Thermochemical Production Of Oxygen And Hydrogen, Jiaxin Lu, Yongliang Zhang, Luhong Chen, Yan Chen, Ke An, Yasser Shoukry, Xinfang Jin, Zhi-Hao Wang, Sai Mu, Kevin Huang

Faculty Publications

Two-step thermochemical cycles offer a clean route for hydrogen and oxygen production but are typically limited to high temperatures exceeding 1500 °C. Lowering operating temperatures would enable the use of alternative heat sources such as industrial waste heat. Here, we report Pr3ZrOas a new enabling material for efficient intermediate-temperature redox cycling, with thermal reduction at 900 °C in argon and steam oxidation at 400 °C. Pr3ZrOadopts a face-centered cubic structure similar to CeO2 but exhibits significantly greater oxygen deficiency, achieving average oxygen and hydrogen fluxes of 331.7 and 70.3 µmol·g-1, respectively, …


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 …


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 …


Joint Neutrino Oscillation Analysis From The T2k And Nova Experiments, S. Abubakar, M. A. Acero, B. Acharya, P. Adamson, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, D. Azevedo, A. Back, N. Balashov, P. Baldi, A. Bambah, E. F. Barenboim, A. Bashyal, A. Basti, K. Bromberg, N. Buchanan, Roberto Petti Oct 2025

Joint Neutrino Oscillation Analysis From The T2k And Nova Experiments, S. Abubakar, M. A. Acero, B. Acharya, P. Adamson, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, D. Azevedo, A. Back, N. Balashov, P. Baldi, A. Bambah, E. F. Barenboim, A. Bashyal, A. Basti, K. Bromberg, N. Buchanan, Roberto Petti

Faculty Publications

The landmark discovery that neutrinos have mass and can change type (or flavour) as they propagate—a process called neutrino oscillation1,2,3,4,5,6—has opened up a rich array of theoretical and experimental questions being actively pursued today. Neutrino oscillation remains the most powerful experimental tool for addressing many of these questions, including whether neutrinos violate charge-parity (CP) symmetry, which has possible connections to the unexplained preponderance of matter over antimatter in the Universe7,8,9,10,11. Oscillation measurements also probe the mass-squared differences between the different neutrino mass states (Δm2), whether there are two light states and a heavier …


Detecting Polar Ring Galaxies Via Deep Learning, Fawad Kirmani, Anathavishnu S. Unnii, Varsha P. Kulkarni, Kyle Lackey, John R. Rose Oct 2025

Detecting Polar Ring Galaxies Via Deep Learning, Fawad Kirmani, Anathavishnu S. Unnii, Varsha P. Kulkarni, Kyle Lackey, John R. Rose

Faculty Publications

Polar ring galaxies (PRGs) are peculiar galaxies that show a ring of stars, gas, and dust oriented roughly over the poles of the central ‘host’ galaxy (i.e. roughly orthogonal to the disc of the host galaxy). The formation models for these rings involve mergers or tidal interactions of the host galaxy with another galaxy. Although the identified PRGs look different from each other, they all have a ring that is not in the same plane as the disc of the host galaxy. Unlike in galaxies such as our Milky Way, where stars form in spiral arms, the rings exemplify an …


Gravitational Perturbations And Quantum Field Interactions In Modified Spacetime Backgrounds, Abhishek Rout Oct 2025

Gravitational Perturbations And Quantum Field Interactions In Modified Spacetime Backgrounds, Abhishek Rout

Theses and Dissertations

This dissertation presents a study of gravitational perturbations and quantum field dynamics in modified spacetime backgrounds. The research is motivated by the quest to understand how quantum fields behave in curved spacetimes, particularly when extensions to general relativity, such as Chern--Simons modifications, are introduced.

The first part examines quantum field interactions with oscillating solitonic backgrounds, inspired by breather-type solutions of the sine--Gordon equation. Fermion bound states are shown to undergo destabilization due to the oscillatory background, leading to particle production and flux propagation to infinity. These results highlight the challenges of maintaining localized fermionic states in time-dependent topological backgrounds.

The …


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 Aug 2025

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 …


Table Of Contents Jul 2025

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Electroexcitation Of Nucleon Resonances And Emergence Of Hadron Mass, Patrick Achenbach, Daniel S. Carman, Ralf Gothe, Kyungseon Joo, Victor I. Mokeev, Craig D. Roberts Jul 2025

Electroexcitation Of Nucleon Resonances And Emergence Of Hadron Mass, Patrick Achenbach, Daniel S. Carman, Ralf Gothe, Kyungseon Joo, Victor I. Mokeev, Craig D. Roberts

Faculty Publications

Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance (N*) electroexcitation amplitudes (or γvpN*) obtained from experiments during the 6 GeV era in Hall B at Jefferson Lab on understanding EHM. Analyzed using continuum Schwinger function methods (CSMs), these results have revealed new pathways for the elucidation of EHM. A good description of the Δ (1232) 3/2+, N (1440) 1/2+, and Δ (1600) 3/2+ …


Two Dimensional Van Der Waals Magnet, Cheongheon Lee Jul 2025

Two Dimensional Van Der Waals Magnet, Cheongheon Lee

Theses and Dissertations

Conventional charge-based memory has reached its limits in improving energy efficiency while scaling down size. Consequently, memory utilizing 2D magnetic materials has emerged as an alternative. 2D Van der Waals (VdW) magnets are ultrathin magnets with unique properties that make them optimal for this purpose. Utilizing the weak interlayer coupling via VdW interaction has enhanced the possibility of integrating diverse materials to create heterostructures. The integration of spintronics requires not only stable magnetization but also an effective switching mechanism. Various external influences have been experimentally tested, such as the proximity effect, external magnetic field, gate voltage, and temperature dependence. This …


The Role Of Symmetries In Atomic, Electromagnetic, And Particle Physics, Joshua Martin O'Connor Jul 2025

The Role Of Symmetries In Atomic, Electromagnetic, And Particle Physics, Joshua Martin O'Connor

Theses and Dissertations

Symmetries in atomic, electromagnetic, and weak interaction physics are explored to understand symmetry-breaking extensions of the Standard Model of particle physics. Lorentz-violating field theories are extremely interesting theoretically, since they possess many new features that are absent in Lorentz-invariant models. We outline the formalism and experimental status of the Lorentz- and CPT-violating Standard Model Extension, in both the classical and quantum regimes. Processes such as vacuum Cerenkov radiation, which are kinematically forbidden when Lorentz symmetry is exact may become allowed when this symmetry is weakly broken. Particle decays, such as pion and kaon decays, although allowed in Lorentz-invariant theories, are …


Uncovering Multiscale Structure-Property Correlations Via Active Learning In Scanning Tunneling Microscopy, Ganesh Narasimha, Deja Kong, Paras Regmi, Rongying Jin, Zheng Gai, Rama Vasudevan, Maxim Ziatdinov Jun 2025

Uncovering Multiscale Structure-Property Correlations Via Active Learning In Scanning Tunneling Microscopy, Ganesh Narasimha, Deja Kong, Paras Regmi, Rongying Jin, Zheng Gai, Rama Vasudevan, Maxim Ziatdinov

Faculty Publications

Atomic arrangements and local sub-structures fundamentally influence emergent material functionalities. These structures are conventionally probed using spatially resolved studies and the property correlations are deciphered by a researcher based on sequential explorations, thereby limiting the efficiency and scope. Here we demonstrate a multi-scale Bayesian deep-learning based framework that automatically correlates material structure with its electronic properties using scanning tunneling microscopy (STM) measurements in real-time. Its predictions are used to autonomously direct exploration toward regions of the sample that optimize a given material property. This method is deployed on a low-temperature ultra-high vacuum STM to understand the structure-property relationship in a …


Jwst Reveals The Diversity Of Nuclear Obscuring Dust In Nearby Agn: Nuclear Isolation Of Miri/Mrs Data Cubes And Continuum Spectral Fitting, Omaira González-Martín, Daniel J. Díaz-González, Mariela Martínez-Paredes, Almudena Alonso-Herrero, Enrique López-Rodríguez, Begoña García-Lorenzo, Cristina Ramos Almeida, Ismael García-Bernete, Donaji Esparza-Arredondo, Sebastian F. Hoenig, Santiago García-Burillo, Chris Packham, Nancy A. Levenson, Alvaro Labiano, Miguel Pereira-Santaella, Francoise Combes, Anelise Audibert, Erin K.S. Hicks, Lulu Zhang, Enrica Bellocchi, Richard I. Davies, Laura Hermosa Muñoz, Masatoshi Imanishi, Claudio Ricci, Marko Stalevski May 2025

Jwst Reveals The Diversity Of Nuclear Obscuring Dust In Nearby Agn: Nuclear Isolation Of Miri/Mrs Data Cubes And Continuum Spectral Fitting, Omaira González-Martín, Daniel J. Díaz-González, Mariela Martínez-Paredes, Almudena Alonso-Herrero, Enrique López-Rodríguez, Begoña García-Lorenzo, Cristina Ramos Almeida, Ismael García-Bernete, Donaji Esparza-Arredondo, Sebastian F. Hoenig, Santiago García-Burillo, Chris Packham, Nancy A. Levenson, Alvaro Labiano, Miguel Pereira-Santaella, Francoise Combes, Anelise Audibert, Erin K.S. Hicks, Lulu Zhang, Enrica Bellocchi, Richard I. Davies, Laura Hermosa Muñoz, Masatoshi Imanishi, Claudio Ricci, Marko Stalevski

Faculty Publications

We investigate the capabilities of the mid-infrared instrument (MIRI) of JWST to advance our knowledge of active galactic nucleus (AGN) dust using the spectral fitting technique on an AGN collection of 21 nearby (z < 0.05) AGN (7 type-1 and 14 type-2) observations obtained with the medium resolution spectroscopy (MRS) mode. This collection includes publicly available AGN and data from the collaboration of Galactic Activity, Torus, and Outflow Survey (GATOS). We developed a tool named MRSPSFisol that decomposes MRS cubes into point-like and extended contributions. We found statistically good fits for 12 targets with current AGN dust models. The model that provides good fits (χ2/dof< 2) for these 12 targets assumes a combination of clumpy and smooth distribution of dust in a flare-disc geometry where the dust grain size is a free parameter. Still, two and one AGN statistically prefer the disc + wind and the classical clumpy torus model, respectively. However, the currently available models fail to reproduce 40 per cent of the targets, likely due to the extreme silicate features not well reproduced by the models and signatures of water-ice and aliphatic hydrocarbon absorption features in most targets. New models exploring, for instance, new chemistry, are needed to explain the complexity of AGN dust continuum emission observed by JWST.


Dust And Metals In Distant Galaxies, Fatima Elkhatib Apr 2025

Dust And Metals In Distant Galaxies, Fatima Elkhatib

Theses and Dissertations

Interstellar dust causes reddening and dimming of light from background objects. To analyze how different the dust in distant galaxies is compared to dust in nearby galaxies, we look at multiple background quasars and try to fit their spectra with various models for known galaxies that have differing dust grain populations combined with a quasar spectrum template. Through fitting these models, we found that dust in most of the foreground galaxies we analyzed is similar to the SMC bar, a relatively thin area selected from the Small Magellanic Cloud (SMC). However, we note that all the objects we studied did …


Photometric Redshifts Of Galaxies In Quasar Fields, Ananthavishnu Santhigiri Unni Apr 2025

Photometric Redshifts Of Galaxies In Quasar Fields, Ananthavishnu Santhigiri Unni

Theses and Dissertations

Understanding the gas in and around galaxies is crucial for understanding galaxy evolution. Absorption lines detected in the spectra of background quasars offer a powerful tool to study the gas in and around the intervening galaxies. As a part of an effort to understand how the gas interacts with the stellar component of galaxies, our team previously obtained imaging and spectroscopic observations for a large sample of galaxies using the Hubble Space Telescope (HST), the Very Large Telescope (VLT), and the Atacama Large Millimeter Array (ALMA). This sample includes thousands of galaxies, including many without spectroscopic data. The overall goal …


Deep Learning-Based Superconductivity Prediction And Experimental Tests, Daniel Kaplan, Adam Zheng, Joanna Blawat, Rongying Jin, Robert J. Cava, Viktor Oudovenko, Gabriel Kotliar, Anirvan M. Sengupta, Weiwei Xie Jan 2025

Deep Learning-Based Superconductivity Prediction And Experimental Tests, Daniel Kaplan, Adam Zheng, Joanna Blawat, Rongying Jin, Robert J. Cava, Viktor Oudovenko, Gabriel Kotliar, Anirvan M. Sengupta, Weiwei Xie

Faculty Publications

The discovery of novel superconducting materials is a long-standing challenge in materials science, with a wealth of potential for applications in energy, transportation and computing. Recent advances in artificial intelligence (AI) have enabled expediting the search for new materials by efficiently utilizing vast materials databases. In this study, we developed an approach based on deep learning (DL) to predict new superconducting materials. We have synthesized a compound derived from our DL network and confirmed its superconducting properties in agreement with our prediction. Our approach is also compared to previous work based on random forests (RFs). In particular, RFs require knowledge …


Bound States And Particle Production By Breather-Type Background Field Configurations, Abhishek Rout, Brett Altschul Nov 2024

Bound States And Particle Production By Breather-Type Background Field Configurations, Abhishek Rout, Brett Altschul

Faculty Publications

We investigate the interaction of fermion fields with oscillating domain walls, inspired by breather-type solutions of the sine-Gordon equation, a nonlinear system of fundamental importance. Our study focuses on the fermionic bound states and particle production induced by a time-dependent scalar background field. The fermions couple to two domain walls undergoing harmonic motion, and we explore the resulting dynamics of the fermionic wave functions. We demonstrate that while fermions initially form bound states around the domain walls, the energy provided by the oscillatory motion of the scalar field induces an outward flux of fermions and antifermions, leading to particle production …


A Low Density Tracker For The Dune Nd Complex., Nibir Talukdar Oct 2024

A Low Density Tracker For The Dune Nd Complex., Nibir Talukdar

Theses and Dissertations

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long- baseline neutrino experiment aimed at resolving mass hierarchy and the CP violation puzzle in the neutrino sector. Although neutrinos are the most abundant particles in the universe, their study is challenging due to their extremely low interaction cross sections. DUNE aims to overcome these challenges by sending a beam of muon (anti)neutrinos from Fermilab, located near Chicago, to the Sanford Underground Research Facility (SURF) in South Dakota.

The experiment consists of a near detector (ND) complex at Fermilab, which mea- sures the composition of the unoscillated neutrino beam, and a …


Topics In Beyond The Standard Model Physics, Sapan Karki Oct 2024

Topics In Beyond The Standard Model Physics, Sapan Karki

Theses and Dissertations

Standard Model and General relativity are two pillars of modern physics, and their reconciliation would bring a long-sought harmony in physics along with insights into the secrets of the universe. It is then natural to try and modify these theories by searching for the fundamental symmetry describing our world. In this work, I work on the implication of breaking of Lorentz symmetry and the existence of topological objects called solitons. In chapter 3, I show how a cosmologically generated Lorentz- Violating model has instability issues. I then show how the quantum corrections on Lorentz-Violating models can produce ambiguity in β-function …


Nonlinear Optical Studies Of Complex Materials, Govinda Kharal Oct 2024

Nonlinear Optical Studies Of Complex Materials, Govinda Kharal

Theses and Dissertations

This dissertation presents an in-depth exploration of nonlinear optical investigations into complex material systems, employing second harmonic generation (SHG) and complementary bulk measurement techniques. The first project focuses on surface symmetries and phase transitions in IrTe2. Using SHG and electrical resistance measurements, we systematically investigate temperature-induced symmetry changes and reveal significant shifts in transition temperatures due to thermal cycling. Comparison with bulk X-ray diffraction confirms that these shifts are surface-related, providing a new interpretation of inconsistencies in reported transition temperatures. Our findings emphasize the effectiveness of SHG in capturing subtle surface phenomena, with future directions involving straincontrolled studies to manipulate …


Measurement Of Single Differential Cross Sections, Polarization Observables, And Beam-Spin Asymmetry In Charged Two-Pion Electroproduction Off The Proton, Christopher Andrew Mclauchlin Oct 2024

Measurement Of Single Differential Cross Sections, Polarization Observables, And Beam-Spin Asymmetry In Charged Two-Pion Electroproduction Off The Proton, Christopher Andrew Mclauchlin

Theses and Dissertations

Emergent phenomena are described as such due to functional differences in paradigms based on observation scale, one of the most fundamental being the emergence of hadronic structure from bare quarks and gluons, as dictated by the strong interaction. Measurement of charged two-pion electroproduction off the proton with CLAS in run group E1-6 and the extraction of single differential cross sections, polarization observables, and beam-spin asymmetries was performed as a necessary step in illuminating the length scale currently dark to Quantum Chromodynamics within the structure of the proton. Understanding the scale-dependent nature of this hadronic structure is integral to understanding nature …