Other Physics Commons^™

Entropic Dynamics Approach To The Classical Limit Of Quantum Mechanics: Decoupling Of The Center Of Mass Motion For A Mesoscopic Particle, Fatimah Judayba

Electronic Theses & Dissertations (2024 - present)

In the Entropic Dynamics (ED) approach, quantum mechanics is derived from the principles of entropic inference and information geometry. The ED approach differs from other interpretations by making a clear commitment to distinguishing which variables are ontic (real) and which are epistemic. The classical limit for the center of mass (CM) coordinate is achieved for a large number of particles, M →∞, while Planck’s constant ℏ remains finite. Typically, the emergence of the classical limit requires decoherence through interactions with the external environment. In this work, we investigate whether the classical behavior of the CM coordinate in a mesoscopic system …

Backgrounds And Efficiencies For Low-Energy Searches, And Improved Calibration Techniques In The Lux-Zeplin Dark Matter Experiment, Gregory M. Blockinger

Electronic Theses & Dissertations (2024 - present)

The full understanding of dark matter has eluded physicists for many years. While there is abundant astrophysical evidence across many scales, the exact nature of this matter, which comprises about 25% of the Universe’s energy density, remains unknown. Weakly Interacting Massive Particles (WIMPs) are one of the leading theoretical candidates, and numerous ex- periments have searched for their interactions. In recent decades, dual-phase Time Projection Chambers (TPCs) have become the leading technology in this search. The LUX-ZEPLIN (LZ) detector is one such xenon-based experiment, operating nearly a mile underground in the Black Hills of South Dakota at the Sanford Underground …

Al(X)In(Y)Ga(1−X−Y)N-Based Monolithically Integrated Ir Detector-Visible Emitter Device, Alireza Lanjani

Electronic Theses & Dissertations (2024 - present)

III-Nitride material system has been widely used in electronic, sensing, optoelectronic, and power device applications. Owing to the wide and tunable bandgap of this material system and the realization of relatively high conductivity p-type Mg-doped GaN films, considerable research over the past few decades has focused on applications based on wide bandgaps, such as blue and ultraviolet (UV) light-emitting diodes (LEDs), laser diodes, visible-blind and solar-blind photodetectors. The other side of the spectrum, infrared (IR) has remained considerably less explored.

To exploit III-Nitrides for IR detection applications, the quantum well infrared photodetector (QWIP) design is employed. In the QWIP …

Probability Distributions Of The Scalar Potential, Candace Mathews

Legacy Theses & Dissertations (2009 - 2024)

In the study of cosmological inflation, string theory and supersymmetry have motivated a wide range of possible inflationary models. These models can be parameterized by a scalar potential V, which is a function of N scalar fields, and determines cosmological parameters such as the vacuum stability and energy density. In principle, we can determine V through high energy physics, such as string theory. In practice, though we may not know the details of V we might have clues about a distribution of plausible V’s, which we can build statistics on to further analyze. The purpose of this thesis defense is …

Calculational Methods In Conformal Field Theory, Thomas Andrew Vandermeulen

Legacy Theses & Dissertations (2009 - 2024)

We examine conformal field theories and their gaugings (orbifolds), first on the torus and then on surfaces of higher genus. Specific attention is paid to performing explicit calculations, to which end we introduce a number of specialized formalisms. Namely, the technology of flavored partition functions allows for a general treatment of orbifolds in theories with conserved currents, and Arakelov geometry facilitates the derivation of novel expressions for geometric quantities appearing commonly on higher genus worldsheets. Ultimately, we leverage the resulting expressions in the calculation of correlation functions via degeneration of Riemann surfaces.

The Foundations Of Inference And Its Application To Fundamental Physics, Nicholas Matthew Carrara

Legacy Theses & Dissertations (2009 - 2024)

This thesis concerns the foundations of inference – probability theory,entropic inference, information geometry, etc. – and its application to the Entropic Dynamics (ED) approach to Quantum Mechanics (QM) [21, 22, 41, 53, 56–61, 150–153, 165, 195, 196, 268]. The first half of this thesis, chapters 2-6, concern the development of the inference framework. We begin in chapter 2 by discussing de- ductive inference, which involves formal logic and it’s role in access- ing the truth of propositions. We eventually discover that deductive inference is incomplete, in that it can’t address situations in which we have incomplete information. This necessitates a …

The Entropic Dynamics Of Relativistic Quantum Fields In Curved Space-Time, Selman Ipek

Legacy Theses & Dissertations (2009 - 2024)

It has often been the case in history that the laws of physics have been used as the framework for understanding and implementing information processing. The tacit assumption is that the laws of physics are fundamental and that the notion of information is derived from these laws. Here we take the opposite view: the laws of physics are an application of the rules for processing information. The inferential framework of entropic dynamics (ED) has previously been developed by A. Caticha for the purposes of understanding and deriving quantum theory, in much the same way that E.T. Jaynes used the MaxEnt …

The Inferential Design Of Entropy And Its Application To Quantum Measurements, Kevin Vanslette

Legacy Theses & Dissertations (2009 - 2024)

This thesis synthesizes probability and entropic inference with Quantum Mechanics and quantum measurement [1-6]. It is shown that the standard and quantum relative entropies are tools \emph{designed} for the purpose of updating probability distributions and density matrices, respectively [1]. The derivation of the standard and quantum relative entropy are completed in tandem following the same inferential principles and design criteria. This provides the first design derivation of the quantum relative entropy while also reducing the number of required design criteria to two.

The Entropic Dynamics Approach To The Paradigmatic Quantum Mechanical Phenomena, Susan Difranzo

Legacy Theses & Dissertations (2009 - 2024)

Standard Quantum Mechanics, although successful in terms of calculating and predicting

Black Hole Microstates & Integrable Deformation In String Theory, Jia Tian

Legacy Theses & Dissertations (2009 - 2024)

In this thesis, we study microstate geometries of black holes in string theory and explore several aspects of integrabile Conformal Field Theories (CFTs).

Hidden Symmetries In String Theory, Iurii Chervonyi

Legacy Theses & Dissertations (2009 - 2024)

In this thesis we study hidden symmetries within the framework of string theory. Symmetries play a very important role in physics: they lead to drastic simplifications, which allow one to compute various physical quantities without relying on perturbative techniques.

Black Hole Microstates In String Theory, Joseph Lewkowicz

Legacy Theses & Dissertations (2009 - 2024)

String theory has resolved the information paradox associated with entropy of black holes by identifying microscopic states contributing to this entropy. This thesis reviews the origin of the paradox, and discusses the progress in resolving it, starting from the counting of states by Strominger and Vafa, and culminating in the current work on constructing fuzzball geometries. A particular emphasis is given to a promising technique for constructing new geometries known as spectral flow.

A Potential Foundation For Emergent Space-Time, Kevin H. Knuth, Newshaw Bahreyni

Physics Faculty Scholarship

We present a novel derivation of both the Minkowski metric and Lorentz transformations from the consistent quantification of a causally ordered set of events with respect to an embedded observer. Unlike past derivations, which have relied on assumptions such as the existence of a 4-dimensional manifold, symmetries of space-time, or the constant speed of light, we demonstrate that these now familiar mathematics can be derived as the unique means to consistently quantify a network of events. This suggests that space-time need not be physical, but instead the mathematics of space and time emerges as the unique way in which an …

Physics: Rethinking The Foundations, Kevin H. Knuth

Physics Faculty Scholarship

Physics is traditionally conceived of as a set of laws that universally governs the behavior of physical systems. These laws, however they are decreed, are believed to govern the behavior of not only everything in the universe, but the form of the universe itself. However, this traditional concept of physics as a universal governance is at odds with our modern theories of quantum mechanics and relativity, which place the observer and information in a central role. In this talk, I aim to rethink the foundations and attempt to build physics from the bottom up based on a very simple foundational …

Momentum And Spin In Entropic Quantum Dynamics, Shahid Nawaz

Legacy Theses & Dissertations (2009 - 2024)

We study quantum theory as an example of entropic inference. Our goal is to remove conceptual difficulties that arise in quantum mechanics. Since probability is a common feature of quantum theory and of any inference problem, we briefly introduce probability theory and the entropic methods to update probabilities when new information becomes available. Nelson's stochastic mechanics and Caticha's derivation of quantum theory are discussed in the subsequent chapters. Our first goal is to understand momentum and angular momentum within an entropic dynamics framework and to derive the corresponding uncertainty relations. In this framework momentum is an epistemic concept -- it …

Information-Based Physics: An Intelligent Embedded Agent's Guide To The Universe, Kevin H. Knuth

Physics Faculty Scholarship

In this talk, I propose an approach to understanding the foundations of physics by considering the optimal inferences an intelligent agent can make about the universe in which he or she is embedded. Information acts to constrain an agent’s beliefs. However, at a fundamental level, any information is obtained from interactions where something influences something else. Given this, the laws of physics must be constrained by both the nature of such influences and the rules by which we can make inferences based on information about these influences. I will review the recent progress we have made in this direction. This …

Generalized Galilean Transformations And The Measurement Problem In The Entropic Dynamics Approach To Quantum Theory, David Terence Johnson

Legacy Theses & Dissertations (2009 - 2024)

Quantum mechanics is an extremely successful and accurate physical theory, yet since its inception, it has been afflicted with numerous conceptual difficulties. The primary subject of this thesis is the theory of entropic quantum dynamics (EQD), which seeks to avoid these conceptual problems by interpreting quantum theory from an informational perspective.

The Energetic And Wave Function Properties Of Atomic, Molecular, And Solid State Systems : H⁻ Ion And The Li, Ne, And P Atoms, Bf3·Nh3 Molecular Complex And Methyl Derivatives, V2+, Cr+, Mn2+, Mn0 Transition Metal Impurities In Silicon, Roger H. Pink

Legacy Theses & Dissertations (2009 - 2024)

The variational Hartree-Fock-Roothaan (HF) method with correlation corrections introduced through Many Body Perturbation Theory (MBPT) and the variational Density Functional Theory (DFT) have been investigated for atomic systems to provide insights into the strengths and weaknesses of each variational approach to solving the multicenter many-electron Hamiltonian. The HF+MBPT method, having been found to be more reliable and physically relevant from the atomic investigations, is used to investigate the electronic structures and associated properties of the BF3*NH3 molecular complex, and through cluster methods, the most likely locations of the transitional metal impurities V2+, Cr+, Mn2+ and Mn0 in Silicon.

First Principles Investigation Of Electronic Structures And Associated Energy And Wave-Function Dependent Properties Of Biological Systems : Deoxyribonucleic Acid (Dna), Oxy-Haemoglobin, Shyam Raj Badu

Legacy Theses & Dissertations (2009 - 2024)

The Hartree-Fock procedure combined with many body perturbation theory has been used to investigate the electronic structures and associated properties of DNA systems and their corresponding muonium (Mu) adducts, as well as oxyhaemoglobin (HbO2).