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Non-Perturbative Aspects Of Gauge Theories Through A Complex Parametrization, Antonina Maj

Dissertations, Theses, and Capstone Projects

This dissertation explores a complex matrix parametrization of four-dimensional non-Abelian gauge theories as a means of gaining analytical insights into (3+1)-dimensional QCD. The low-energy scale of non-Abelian gauge theories remains an elusive area of research even after decades of work. A key challenge lies in identifying physical, gauge-invariant degrees of freedom that are relevant to non-perturbative phenomena. In this dissertation we develop a complex parametrization of gauge fields on which gauge transformations act homogeneously, thereby enabling a manifestly gauge-invariant analytical formulation of the theory.

Chapter one constructs the complex gauge-invariant parametrization for gauge theories living on both complex projective space …

Quantum Entanglement Correlations In The Proton On The Light-Front, Eric Kolbusz

Dissertations, Theses, and Capstone Projects

In this work we gather results on information theory applied to proton tomography. We start by analyzing the quantum entanglement of momentum, spin-flavor, and color degrees of freedom (d.o.f.) in the leading valence-quark state of the proton on the light front using standard information theoretical tools, leveraging model wavefunctions by Brodsky and Schlumpf to obtain numerical predictions. Light-cone perturbation theory allows us to introduce the one-gluon correction in the sub-leading Fock state and study the entanglement of the gluonic d.o.f. We find weak entanglement in the spatial d.o.f. of the valence quarks, and significantly stronger entanglement in the analogous d.o.f. …

The Weight Of Complicity: A Network Analysis Of Ecocide In Palestine, Marilyn Moy

Dissertations, Theses, and Capstone Projects

This paper combines multi-criteria decision analysis (MCDA) with a network graph visualization to examine corporate and institutional involvement in ecocide in Palestine from 1917 to the present. Using a weighted sum model based on UN human rights principles and UNEP guidelines, actors are evaluated across three criteria: directness, scale, and duration of harm. A dataset of 50+ entities, including Caterpillar, Elbit Systems, and the Jewish National Fund, reveals a dense network of responsibility, with major enablers in the construction, tech, and military sectors. Findings highlight the severe impacts of the 2023–present assault on Gaza and demonstrate that ecocide is a …

The Density Distribution Of The Material Around Betelgeuse, Iman Behbehani

Dissertations, Theses, and Capstone Projects

Betelgeuse is a red supergiant star visible in the constellation Orion. Its windy and highly convective surface results in a complicated mass loss pattern difficult to understand and replicate in simulations. The ejected mass can form a shell around the star we consider the circumstellar material (CSM). In this study, we use ALMA interferometric observations to find the structure of Betelgeuse's CSM, and connect to the mass loss mechanisms that could form it. We measure a bipolar circumstellar structure with a position angle of 42.3$\pm 7.0^\circ$. We observe asymmetries in the form of hot spots in the north east of …

Novel Machine Learning Methods For Quasar Variability And Strong Gravitational Lensing, Joshua Fagin

Dissertations, Theses, and Capstone Projects

Machine learning methods are well suited to handle the unprecedented data volume expected from upcoming wide-field surveys. The European Space Agency's Euclid telescope was launched in July 2023 and is expected to observe billions of galaxies at high resolution, including tens of thousands of strongly lensed galaxies. The Rubin Observatory Legacy Survey of Space and Time (LSST) will monitor tens of millions of quasars throughout its ten-year lifetime, thousands of which will be strongly lensed. This flood of data will enable measuring lens galaxy mass distributions and substructure, as well as probing quasar accretion disk structure and black hole properties …

An Interpolating Regime For The Extreme Values Of A Random Zeta Model, Christine K. Chang

Dissertations, Theses, and Capstone Projects

We study the large values of a random model of the Riemann zeta function over short intervals. The extreme value statistics depend on the interval size: the log-correlated regime governs intervals of order one while the i.i.d. regime emerges over longer intervals. The main focus is to describe the transition between these two well-understood regimes as the interval varies in length. This thesis shows that there is an intermediate regime where the behavior of the zeta model’s maxima cannot be entirely captured by either extreme— i.i.d. or fully log-correlated. This suggests that the Riemann zeta function exhibits correlations around its …

Nonlinear Optics Through Femtosecond Light-Matter Interactions, Shah Faisal B. Mazhar

Dissertations, Theses, and Capstone Projects

This dissertation offers experimental and theoretical insights into nonlinear light-matter interactions induced by intense femtosecond (fs) laser pulses. It investigates key phenomena, including stimulated Raman scattering (SRS) from phonon and magnon quasiparticles, supercontinuum (SC) generation via self-phase modulation (SPM), conical emission (CE) arising from four-wave mixing (4WM), and modulation instability (MI) driven by cross-phase modulation (XPM) between SRS and SC processes. These effects are studied in diverse media using state-of-the-art femtosecond lasers.

The interplay among SRS, SC, 4WM, and MI is examined to probe vibrational modes and temperature-dependent magnetic excitations in condensed-matter systems. Experiments are conducted on anisotropic uniaxial calcite …

Leveraging Stellar Chemistry For A Global View Into The Atmospheres Of Brown Dwarfs And Giant Exoplanets, Emily Calamari

Dissertations, Theses, and Capstone Projects

In the era of the James Webb Space Telescope (JWST), it is now possible to examine substellar mass atmospheres in unparalleled detail and precision. However, unraveling the complicated thermodynamics and chemistry in these atmospheres remains a challenge. Atmospheric retrievals are a leading data-driven technique capable of recovering an object’s fundamental parameters such as mass, radius, effective temperature, gravity, cloud structure and composition and chemical abundances. However, in directly imaged or isolated worlds, constraining and/or interpreting these fundamental parameters can be difficult, particularly as retrieval models try to parameterize the overall impact of clouds.

For my dissertation, I turned to main …

Multi-Nuclear Magnetic Resonance (Nmr) Characterization Of Novel Materials, Tawhid Pranto

Dissertations, Theses, and Capstone Projects

The increasing reliance on batteries in commercial products, coupled with the environmental challenges posed by climate change and the limitations of fossil fuel consumption, has created strong financial and environmental incentives to explore innovative energy storage solutions. Renewable energy sources are being actively developed, but their intermittent nature necessitates efficient storage technologies, driving significant research into improving the performance of batteries, fuel cells, and capacitors.

This thesis focuses on the application of advanced Nuclear Magnetic Resonance (NMR) spectroscopy to study and understand novel materials for energy storage applications, with an emphasis on electrolytes for rechargeable lithium-ion batteries and all-solid-state batteries. …

Nuclear Magnetic Resonance Characterization For The Study Of Beyond Lithium-Ion Battery Electrolytes, Allen Zheng

Dissertations, Theses, and Capstone Projects

To achieve a sustainable future, key issues in the energy and construction sectors such as the transition from fossil fuels to renewable energy sources and recycling of waste construction materials must be addressed. While fossil fuels offer a high energy density source of quick, consistent energy, renewable energy sources such as wind, solar, and hydroelectric offer intermittent energy output, requiring energy storage systems to maintain steady energy availability for consumers. Lithium-ion batteries (LIBs) are widely used in consumer electronics, electric vehicles, and grid storage due to their high energy density, low self-discharge, and rechargeability. However, they are limited by high …

Developments In The Lithographic Engineering Of Bi2sr2cacu2o8+Delta Mesa Terahertz-Emitting Devices, Sarah Elghazoly

Dissertations, Theses, and Capstone Projects

Devices microfabricated from the high-temperature superconducting cuprate Bi₂Sr₂CaCu₂O_8+𝛿 (Bi-2212) are a promising source of coherent terahertz radiation within the ’terahertz gap’ (0.3- 1.5 THz). A current-biased mesa patterned into the surface of a single crystal will produce electromagnetic radiation in the terahertz regime due to the naturally occurring Josephson junctions formed by the stacks of superconducting cuprate oxide planes in the material separated by insulating BiO and SrO barrier layers. Previous research has shown that by fabricating these mesas such that the geometry supports resonant cavity Fabry-Perot modes, the junctions within the mesa …

Refining Orbits And Revealing Origins: A Study Of Giant Exoplanets Around Low-Mass Stars, Angeli Sandoval

Dissertations, Theses, and Capstone Projects

The study of gas giants around low-mass stars offers important insight into planet formation. Core accretion models predict that these planets should have a low likelihood of forming due to the limited disk masses of their host low-mass stars. However, NASA space missions such as Kepler and TESS have revealed an emerging population of Saturn- and Jupiter-like planets around M-dwarfs (referred to as giant exoplanets orbiting M-dwarfs or GEMS) that challenge these expectations. This thesis investigates the detection, confirmation, and analysis of GEMS through pipeline development and a detailed analysis of two systems.

In Chapter 1, I provide background information …

The Role Of Water In Peptide Behavior And Peptide-Based Water-Responsive Crystals, Janel Jannette Rivera Cancel

Dissertations, Theses, and Capstone Projects

Water plays a crucial role in shaping the behavior and function of biomolecules across the liquid, supercooled, and glassy states. This thesis presents a dual approach combining computational simulations and experimental investigations to explore the influence of water on biomolecular systems, particularly peptide-based materials. We employ molecular dynamics simulations to study the hydration-dependent structural dynamics of homopolymer peptides. Simulations were carried out across a range of temperatures and pressures to analyze changes in hydration and structural stability, shedding light on the behavior of peptides under supercooled and glassy conditions. These studies are especially relevant for understanding biomolecular stability in cryopreservation. …

Reinforcement Learning Based Resource Management In Edge Systems, Motahare Mounesan

Dissertations, Theses, and Capstone Projects

Modern end-user applications that are highly compute- and data-intensive, while being extremely latency- and accuracy-sensitive, are increasingly reliant on distributed computing. This paradigm spans a range of architectures, from cloud computing to in-device processing. Cloud computing, though scalable, often incurs high latency and cost, constraints that are particularly problematic for time-sensitive applications. In contrast, in-device computing on end or IoT devices is limited by resource constraints, making it inadequate for many complex workloads. Edge computing presents a compelling alternative by bringing computation closer to data sources, thereby reducing end-to-end latency and improving responsiveness. However, the inherent decentralized and dynamic nature …

Satellite-Host Galaxy Co-Evolution With Next-Generation Regulator Models, Austen Gabrielpillai

Dissertations, Theses, and Capstone Projects

The evolution of satellites galaxies is an unsolved problem in galaxy formation. Recent observations such as the SAGA and ELVES surveys find tension in HI contents and star formation of satellites around their central host galaxies when compared to our own local environment, the Milky Way. These processes are potentially highly influenced by the host's circumgalactic medium (CGM), and to constrain these cases requires accurate and fast modeling of satellites-host interactions. In this work, we present our methodology for evolving z = 0 surviving satellites alongside their central galaxy in sapphire, a CGM regulator co-evolution model of galaxy formation. …

Pine Fruit Activated Carbon Modified With Cuco2se4 For The Application In High-Performance Battery-Type Supercapacitor, Farshad Tavakoli, Ali A. Ensafi, Behzad Rezaei

Chemistry & Biochemistry Faculty Publications and Presentations

Biomass has attracted considerable interest in the field of energy storage because of its outstanding characteristics, such as superior charge transport ability, affordability, eco-friendly, structural versatility, and renewability. Moreover, biomass-derived activated carbons, combined with pseudocapacitive materials, have recently gained popularity as efficient electrochemical components for energy storage devices. In this study, activated carbon was prepared from pinecone flowers as the biomass precursor through a process involving alkaline treatment and pyrolytic carbonization in an inert gas environment. Subsequently, CuCo2Se4 nanoparticles (CCS) were synthesized on the Pine Fruit Activated Carbon (PFAC) surface via a hydrothermal method. CCS serves as a pseudocapacitive material …

Short–Range Hard–Sphere Potential And Coulomb Interaction: Deser–Trueman Formula For Rydberg States Of Exotic Atomic Systems, Gregory S. Adkins, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

In exotic atomic systems with hadronic constituent particles, it is notoriously difficult to estimate the strong-interaction correction to energy levels. It is well known that, due to the strength of the nuclear interaction, the problem cannot be solved using Wigner–Brillouin perturbation theory alone. Recently, high-angular-momentum Rydberg states of exotic atomic systems with hadronic constituents have been identified as promising candidates in the search for new physics in the low-energy sector of the Standard Model. We thus derive a generalized Deser–Trueman formula for the induced energy shift for a general hydrogenic bound state with principal quantum number n and orbital angular …

Guiding Multiple Remote Users In Physical Tasks With Language-Driven Robotic Telepresence, Ruyi Li, Jingfei Guo, Xinyi Zhang, Xuji Zhang, Zeqing Li, Jiannan Li, Jiangtao Gong

Research Collection School Of Computing and Information Systems

Remote assistance through robotic telepresence could involve both control and memory challenges, particularly in one expert to multiple workers situation. In this work, we proposed a novelty language-driven interface to facilitate remote collaboration through telepresence robots. Through operations and maintenance expert interviews and a scenario simulation study, we identified key pain points in executing one-expert-multiple-workers remote guidance using the telepresence robot and proposed two design goals, which together consist of five sub-design goals with corresponding features. These features were integrated into a standard telepresence robot, resulting in the development of a Collaborative LLM-based Embodied Assistant Robot, named CLEAR Robot. A …

Relevant Deformations Of Brane Brick Models, Georgios P. Goulas

Dissertations, Theses, and Capstone Projects

The thesis studies relevant deformations of 2d gauge theories with $\mathcal{N}=(0,2)$ supersymmetry, realized on the worldvolume of D1-branes probing toric Calabi-Yau 4-folds. Brane brick models are the primary means for engineering such theories and streamlining their connection to geometry. In this thesis, we relevant deformations of brane brick models, focusing on a specific class of deformations in which the initial and final theories are both described by brane brick models. Relevant deformations serve as an additional, systematic way of generating these theories, as well as uncovering connections between them. Within the framework of brane engineering, these deformations acquire a geometric …

Nonlinear Diffusion, Hydrodynamic Cascades And Jamming In Kinetically Constrained Systems: Insights From Lattice Gas Models, Abhishek Raj

Dissertations, Theses, and Capstone Projects

This dissertation investigates non-linear diffusion processes and emergent dynamical phenomena in kinetically constrained lattice gases. Two central models are considered: a one-dimensional lattice gas exhibiting a diffusion cascade triggered by hydrodynamic nonlinearities and a triangular ladder exclusion model that undergoes a jamming transition. The former demonstrates stretched exponential decay consistent with non-perturbative long-time tails, while the latter illustrates how classical-quantum mappings yield insight into glassy dynamics and mobility constraints. Through a combination of numerical simulations, analytical perturbation theory, and mean-field approximations, the work uncovers mechanisms underlying anomalous transport, jamming transitions, and the breakdown of perturbative hydrodynamics.

A Difficult Act To Maintain, J.G. Allen

Research Collection Yong Pung How School Of Law

In "Where is Singapore's AI regulation headed?" (Issues, Summer 2025), Manoj Harjani starts by recounting its delicate balancing act in governing artificial intelligence. The city-state is able to maintain credibility on the global stage while remaining pragmatically grounded in technical experimentation, maintaining policy realism without overcommitting to rigid legal frameworks. The choice to adopt a regulatory “light touch” is often framed as a way to maintain flexibility, avoid overregulation, and enable innovation. But this obscures the extent to which this posture is itself a political and economic settlement—one that reinforces Singapore’s position in the global digital economy by facilitating capital …

Bridging The Great Wall: China’S Evolving Cross-Border Data Flow Policies And Implications For Global Data Governance, Sheng Zhang, Henry S. Gao

Research Collection Yong Pung How School Of Law

Despite the rapid expansion of the digital economy, the global regulatory framework for data flows remains fragmented, with countries adopting divergent approaches shaped by their own regulatory priorities. As a key player in the Internet economy, China’s approach to cross-border data flows (CBDF) not only defines its domestic digital landscape but also influences emerging global norms. This paper takes a comprehensive view of the evolution of China’s CBDF regime, examining its development through both domestic and international lenses. Domestically, China’s regulation of CBDF has evolved from a security-first approach to one that seeks to balance security with economic development. This …

Optimal Abort Policy For Mission-Critical Systems Under Imperfect Condition Monitoring, Qiuzhuang Sun, Jiawen Hu, Zhi-Sheng Ye

Research Collection College of Integrative Studies

Although most on-demand mission-critical systems are engineered to be reliable to support critical tasks, occasional failures may still occur during missions. To increase system survivability, a common practice is to abort the mission before an imminent failure. We consider optimal mission abort for a system whose deterioration follows a general three-state (normal, defective, failed) semi-Markov chain. The failure is assumed self-revealed, whereas the healthy and defective states have to be inferred from imperfect condition-monitoring data. Because of the non-Markovian process dynamics, optimal mission abort for this partially observable system is an intractable stopping problem. For a tractable solution, we introduce …

Recurrent Autoregressive Linear Model For Next-Basket Recommendation, Tereza Zmeskalova, Antoine Ledent, Martin Spisak, Pavel Kordik, Rodrigo Alves

Research Collection School Of Computing and Information Systems

Next-basket recommendation aims to predict the (sets of) items that a user is most likely to purchase during their next visit, capturing both short-term sequential patterns and long-term user preferences. However, effectively modeling these dynamics remains a challenge for traditional methods, which often struggle with interpretability and computational efficiency, particularly when dealing with intricate temporal dependencies and inter-item relationships. In this paper, we propose ReALM, a Recurrent Autoregressive Linear Model that explicitly captures temporal item-to-item dependencies across multiple time steps. By leveraging a recurrent loss function and a closed-form optimization solution, our approach offers both interpretability and scalability while maintaining …

Storage Location Optimization In Automated Storage And Retrieval Systems: A Deep Reinforcement Learning Approach, Lingjun Wang, Aldy Gunawan, Pieter Vansteenwegen

Research Collection School Of Computing and Information Systems

This study investigates the optimization of storage location in automated storage and retrieval systems (AS/RS). We introduce an optimization approach based on the Deep Q-Network (DQN) algorithm to enhance warehouse task efficiency and minimize stacker travel during storage and retrieval. To accelerate the algorithm training process, we integrate a prioritized experience replay mechanism. Furthermore, we decouple action selection from value estimation within the DQN framework to address the issue of value overestimation. The proposed model is evaluated against three heuristic methods. The experimental results demonstrate that our approach significantly outperforms these baselines.

Towards Automated Evolution Of Imperative Deep Learning Programs, Tatiana Castro-Vélez

Dissertations, Theses, and Capstone Projects

Software engineering (SE) is increasingly intersecting with data-centric domains such as machine learning (ML) and deep learning (DL). Similar to bugs in traditional software systems, defects can emerge in ML and DL systems. ML, including DL, systems are now widespread and rely on dynamic models defined by input data. Developers face the challenge of building dependable systems while addressing the demand for scalable software.

Efficiency is essential to support responsiveness with respect to ever-growing datasets. Traditional DL frameworks achieve scalability through deferred execution, enabling symbolic, graph-based deep neural network (DNN) computation. While efficient, this approach is error-prone, cumbersome, and difficult …

Starspot Inference Using Light Curve Inversion Techniques, Mohammad Refat

Dissertations, Theses, and Capstone Projects

Star spots are patches that are dark or bright on the surface of a star. They are tightly correlated to the magnetic activity of stars. One of the reasons we want to study star spots is to better understand where the active latitude of stars are located, which helps us understand planet habitability around low mass stars. The Starry package is a set of tools that can map the surface of stars and exoplanets using time series data, with spherical harmonics. Butterpy is a package that allows for the simulation of starspot evolution and their lightcurves. Fleck is a package …

How To Form A Gravitational-Wave Source: Quantifying Intermediate Evolutionary Stages In Isolated Binary Stellar Evolution, Ana Lam

Dissertations, Theses, and Capstone Projects

Gravitational-wave (GW) detections from double compact object (DCO) mergers provide crucial observational constraints for understanding massive stars across cosmic time. Coupled with these observations, binary population synthesis simulations become powerful tools for probing the formation, evolution, and ultimate fates of their progenitors---massive binary stars. However, complex evolutionary pathways, shaped by key intermediate stages such as mass transfer phases and supernovae, present a significant challenge to assess their impact. To address this, we develop a framework to quantify the influence of intermediate evolutionary stages on GW sources. By combining Sankey diagrams with survival factors, we systematically investigate how intermediate stages influence …

Effect Of Equation Of State On The Formation Of Binary Black Holes In Active Galactic Nucleus Disks, Theodore Edwards

Dissertations, Theses, and Capstone Projects

Active galactic nucleus disks have been proposed as a possibly dominant location of the mergers of binary black holes detected by gravitational wave observatories. The nonlinear interactions between stellar mass black holes and disk gas determine when binaries will form from single objects on nearby orbits. Prior work has used smoothed particle hydrodynamics models in an isothermal disk to study this problem. However, the local equation of state near the midplane of an optically thick accretion disk is adiabatic rather than isothermal, even if the radiative equilibrium temperature is azimuthally isothermal. Therefore, we investigate the use of an adiabatic equation …

Investigating The Behavior Of Dwarf-Hosting Cosmic Filaments In Regions Of Average Density Within The Universe, Manuel E. Ramirez Hernandez

Dissertations, Theses, and Capstone Projects

The cosmic web is the large-scale structure of the universe, composed of elongated, overdense areas held together by gravity known as cosmic filaments. Within these filaments, dwarf galaxies are ubiquitous and make for excellent laboratories due to their small size. to determine the effects of cosmic web structures on dwarf galaxies. In this thesis, I laid the groundwork to investigate whether dwarf galaxy populations vary across different types of filaments. Filaments were extracted from the gas density field in the New Horizon simulation at $z=0$ using the topological feature finder DisPerSE. I determined the distances of galaxies to their nearest …