# Physics Commons™

Articles 1 - 30 of 524

## Full-Text Articles in Physics

Introduction To Classical Field Theory, Charles G. Torre Aug 2019

#### Introduction To Classical Field Theory, Charles G. Torre

##### All Complete Monographs

This is an introduction to classical field theory. Topics treated include: Klein-Gordon field, electromagnetic field, scalar electrodynamics, Dirac field, Yang-Mills field, gravitational field, Noether theorems relating symmetries and conservation laws, spontaneous symmetry breaking, Lagrangian and Hamiltonian formalisms.

Jun 2019

#### A Tribute To Robert U. Ayres For A Lifetime Of Work In Technological Forecasting And Related Areas, Steven M. Miller

##### Research Collection School Of Information Systems

Bob Ayres was born in the UnitedStates in 1932. For his university studies at the bachelors, masters and PhD levels, he concentrated in physics and mathematics. When we think of Bob today, we think of his pioneering work across the areas of technological forecasting, industrial metabolism and industrial ecology, and the role of energy and thermodynamics in economic growth. How did a person with a strong fundamental education as a physicist end up as a pioneering thinker and thought leader at the intersection of energy, environment and economics?

Pairwise Completely Positive Matrices And Conjugate Local Diagonal Unitary Invariant Quantum States, Nathaniel Johnston, Olivia Maclean May 2019

#### Pairwise Completely Positive Matrices And Conjugate Local Diagonal Unitary Invariant Quantum States, Nathaniel Johnston, Olivia Maclean

##### Electronic Journal of Linear Algebra

A generalization of the set of completely positive matrices called pairwise completely positive (PCP) matrices is introduced. These are pairs of matrices that share a joint decomposition so that one of them is necessarily positive semidefinite while the other one is necessarily entrywise non-negative. Basic properties of these matrix pairs are explored and several testable necessary and sufficient conditions are developed to help determine whether or not a pair is PCP. A connection with quantum entanglement is established by showing that determining whether or not a pair of matrices is pairwise completely positive is equivalent to determining whether or not ...

Co-Sputtered Tibx Thin Films, Alexander Sredenschek May 2019

#### Co-Sputtered Tibx Thin Films, Alexander Sredenschek

##### Honors Projects and Presentations: Undergraduate

Titanium diboride (TiB2) is a ceramic material that has attracted considerable interest due to its distinctive set of properties, such as high melting point and hardness, good thermal and electrical conductivity, as well as excellent corrosion resistance. In some applications, thin coatings of TiB2 may be desired, and one way to obtain such coatings is through the growth of thin films. One common growth technique is magnetron sputtering. However, when films are grown by magnetron-sputtering from a single TiB2 target, differences in preferred ejection angles and gasphase scattering yield B-rich TiBx films with x typically ranging from 2.5 to ...

May 2019

#### Unbounded Derivations Of C*-Algebras And The Heisenberg Commutation Relation, Lara M. Ismert

##### Dissertations, Theses, and Student Research Papers in Mathematics

This dissertation investigates the properties of unbounded derivations on C*-algebras, namely the density of their analytic vectors and a property we refer to as "kernel stabilization." We focus on a weakly-defined derivation δD which formalizes commutators involving unbounded self-adjoint operators on a Hilbert space. These commutators naturally arise in quantum mechanics, as we briefly describe in the introduction.

A first application of kernel stabilization for δD shows that a large class of abstract derivations on unbounded C*-algebras, defined by O. Bratteli and D. Robinson, also have kernel stabilization. A second application of kernel stabilization provides a ...

Apr 2019

#### Brain Network Structure And Interventions In A Computational Model Of Epilepsy, Joe Emerson

##### Student Symposium

Some forms of drug-resistant epilepsy can only be treated via surgical intervention. This form of treatment requires the removal of a part of the brain identified as the seizure source. Current methods for surgical treatment are risky and many times unsuccessful. A deeper understanding of how brain connectivity facilitates seizure propagation is necessary for developing improved surgical techniques. Experimental limitations make certain clinical investigations of epilepsy difficult or impossible, but computational modeling offers a way forward when experimentation in living systems is impractical or unsafe. We used a full-hemisphere computational model for epilepsy to investigate the role of network structure ...

2019 Petersheim Academic Exposition Schedule Of Events, Seton Hall University Apr 2019

#### 2019 Petersheim Academic Exposition Schedule Of Events, Seton Hall University

Quantum Advantages Quantum Algorithm For Finding The Minimum, Binam Bajracharya Apr 2019

#### Quantum Advantages Quantum Algorithm For Finding The Minimum, Binam Bajracharya

##### Senior Theses

Theories about quantum computers and how they would work have been around for a few decades. Peter Shor and Lov Grover even came up with algorithms during the 1990s when the idea of building a quantum computer was far-fetched. We are now at a point where our processors are getting faster and smaller, only a few nanometres thick. This obviously has its limits. Big companies like Google, Microsoft, and IBM are at a point where their quantum computers are equivalent to the room sized computers that we see in some old pictures. Here we build up the necessary background required ...

Apr 2019

#### Semiclassically Modeling Hydrogen At Rydberg States Immersed In Electromagnetic Fields, Jaron Williams

##### Mathematics Senior Capstone Papers

Originally, closed-orbit theory was developed in order to analyze oscillations in the near ionization threshold (Rydberg) densities of states for atoms in strong external electric and magnetic fields. Oscillations in the density of states were ascribed to classical orbits that began and ended near the atom. In essence, observed outgoing waves following the classical path return and interfere with original outgoing waves, giving rise to oscillations. Elastic scattering from one closed orbit to another gives additional oscillations in the cross-section. This study examines how quantum theory can be properly used in combination with classical orbit theory in order to study ...

Mar 2019

#### Schlieren Imaging And Flow Analysis On A Cone/Flare Model In The Afrl Mach 6 Ludwieg Tube Facility, David A. Labuda

##### Theses and Dissertations

High-speed Schlieren photography was utilized to visualize flow in the Air Force Research Laboratory Mach 6 Ludwieg tube facility. A 7° half-angle cone/flare model with variable nosetip radius and flare angle options was used in the study. Testing was performed at two driver tube pressures, generating freestream Reynolds numbers of 10.0x106 and 19.8x106 per meter. The variable-angle flare portion of the model provided a method for adjusting the intensity of the adverse pressure gradient at the cone/flare junction. As expected from existing literature, boundary layer separation along the cone frustum occurred further upstream as ...

Wall Model Large Eddy Simulation Of A Diffusing Serpentine Inlet Duct, Ryan J. Thompson Mar 2019

#### Wall Model Large Eddy Simulation Of A Diffusing Serpentine Inlet Duct, Ryan J. Thompson

##### Theses and Dissertations

The modeling focus on serpentine inlet ducts (S-duct), as with any inlet, is to quantify the total pressure recovery and ow distortion after the inlet, which directly impacts the performance of a turbine engine fed by the inlet. Accurate prediction of S-duct ow has yet to be achieved amongst the computational fluid dynamics (CFD) community to improve the reliance on modeling reducing costly testing. While direct numerical simulation of the turbulent ow in an S-duct is too cost prohibitive due to grid scaling with Reynolds number, wall-modeled large eddy simulation (WM-LES) serves as a tractable alternative. US3D, a hypersonic research ...

Analytical Wave Solutions Of The Space Time Fractional Modified Regularized Long Wave Equation Involving The Conformable Fractional Derivative, M. Hafiz Uddin, Md. Ashrafuzzaman Khan, M. Ali Akbar, Md. Abdul Haque Mar 2019

#### Analytical Wave Solutions Of The Space Time Fractional Modified Regularized Long Wave Equation Involving The Conformable Fractional Derivative, M. Hafiz Uddin, Md. Ashrafuzzaman Khan, M. Ali Akbar, Md. Abdul Haque

##### Karbala International Journal of Modern Science

The space time fractional modified regularized long wave equation is a model equation to the gravitational water waves in the long-wave occupancy, shallow waters waves in coastal seas, the hydro-magnetic waves in cold plasma, the phonetic waves in dissident quartz and phonetic gravitational waves in contractible liquids. In nonlinear science and engineering, the mentioned equation is applied to analyze the one way tract of long waves in seas and harbors. In this study, the closed form traveling wave solutions to the above equation are evaluated due to conformable fractional derivatives through double (G'⁄G,1⁄G)-expansion method and the ...

Comforting With Mathematics: A Case Study, Michael J. Goldstein Jan 2019

#### Comforting With Mathematics: A Case Study, Michael J. Goldstein

##### Journal of Humanistic Mathematics

Death by suicide often leaves behind grieving family members with unanswered questions. Of these concerns, fear that their loved one suffered or felt regret is common. When the method of suicide was jumping from height, that answer can easily be determined using basic kinematics. Despite the perception that mathematics is a cold, calculating field, it can provide a clear, definitive answer and comfort those left behind.

Mechanisms For Fracton Phases, Han Ma Jan 2019

#### Mechanisms For Fracton Phases, Han Ma

##### Physics Graduate Theses & Dissertations

Strongly correlated many-body systems provide a platform for novel phases of matter where constituent particles organize themselves in a variety of ways. At low temperature, these particles interact quantum mechanically and generate entanglement building up exotic quantum phases, such as topologcial order, where there can be emergent excitations which cannot be created locally. Such excitations, if gapped, are also called topological excitations.

Fracton is one of such gapped point-like topological excitation in three dimensional system. Different from conventional topological excitation, it is immobile and was firstly discovered in exact solvable models exhibiting fracton topological order. This new order has sub-extensive ...

Volume 11, Jacob Carney, Ryan White, Joseph Hyman, Jenny Raven, Megan Garrett, Ibrahim Kante, Summer Meinhard, Lauren Johnson, William "Editha" Dean Howells, Laura Gottschalk, Christopher Siefke, Pink Powell, Natasha Woodmancy, Katharine Colley, Abbey Mays, Charlotte Potts Jan 2019

#### Volume 11, Jacob Carney, Ryan White, Joseph Hyman, Jenny Raven, Megan Garrett, Ibrahim Kante, Summer Meinhard, Lauren Johnson, William "Editha" Dean Howells, Laura Gottschalk, Christopher Siefke, Pink Powell, Natasha Woodmancy, Katharine Colley, Abbey Mays, Charlotte Potts

##### Incite: The Journal of Undergraduate Scholarship

Introduction, Dr. Roger A. Byrne, Dean

From the Editor, Dr. Larissa "Kat" Tracy

From the Designers, Rachel English, Rachel Hanson

Synthesis of 3,5-substituted Parabens and their Antimicrobial Properties, Jacob Coarney, Ryan White

Chernobyl: Putting "Perestroika" and "Glasnot" to the Test, Joseph Hyman

Art by Jenny Raven

Why Has the Democratic Republic of the Congo outsourced its Responsibility to Educate its Citizens? Ibrahim Kante

Art by Summer Meinhard

A Computational Study of Single Molecule Diodes, Lauren Johnson

Satire of the State through ...

Deformations Of G2-Structures, String Dualities And Flat Higgs Bundles, Rodrigo De Menezes Barbosa Jan 2019

#### Deformations Of G2-Structures, String Dualities And Flat Higgs Bundles, Rodrigo De Menezes Barbosa

##### Publicly Accessible Penn Dissertations

We study M-theory compactifications on G2-orbifolds and their resolutions given by total spaces of coassociative ALE-fibrations over a compact flat Riemannian 3-manifold Q. The flatness condition allows an explicit description of the deformation space of closed G2-structures, and hence also the moduli space of supersymmetric vacua: it is modeled by flat sections of a bundle of Brieskorn-Grothendieck resolutions over Q. Moreover, when instanton corrections are neglected, we obtain an explicit description of the moduli space for the dual type IIA string compactification. The two moduli spaces are shown to be isomorphic for an important example involving A1-singularities, and the result ...

Surface Waves Over Currents And Uneven Bottom, Alan C. Compelli, Rossen Ivanov, Calin I. Martin, Michail D. Todorov Jan 2019

#### Surface Waves Over Currents And Uneven Bottom, Alan C. Compelli, Rossen Ivanov, Calin I. Martin, Michail D. Todorov

##### Articles

The propagation of surface water waves interacting with a current and an uneven bottom is studied. Such a situation is typical for ocean waves where the winds generate currents in the top layer of the ocean. The role of the bottom topography is taken into account since it also influences the local wave and current patterns. Specific scaling of the variables is selected which leads to approximations of Boussinesq and KdV types. The arising KdV equation with variable coefficients, dependent on the bottom topography, is studied numerically when the initial condition is in the form of the one soliton solution ...

Cross Faculty Collaboration In The Development Of An Integrated Mathematics And Science Initial Teacher Education Program, Sharon P. Fraser, Kim Beswick, Margaret Penson, Andrew Seen, Robert Whannell Jan 2019

#### Cross Faculty Collaboration In The Development Of An Integrated Mathematics And Science Initial Teacher Education Program, Sharon P. Fraser, Kim Beswick, Margaret Penson, Andrew Seen, Robert Whannell

##### Australian Journal of Teacher Education

This paper describes a collaborative project involving mathematicians, scientists and educators at an Australian university where an innovative initial teacher education (ITE) degree in mathematics/science was developed. The theoretical frameworks of identity theory and academic brokerage and their use in understanding the challenges associated with the early stages of collaborative projects is described. Data from reflections and interviews of the participants after involvement in the project from one to three years are presented to illustrate these challenges. The paper concludes with a description of the importance of the academic broker in overcoming identity challenges and facilitating cultural change for ...

Symmetry Reduction In K − P Problems, Benjamin Sheller Jan 2019

#### Symmetry Reduction In K − P Problems, Benjamin Sheller

$K-P$ problems are a class of geometric optimal control problems on finite-dimensional real semisimple Lie groups which arise, for example, in the control of quantum systems when the Lie group is $SU(n)$. In these problems, the sub-Riemannian distribution corresponds to the $\p$-part of a Cartan decomposition (also known as the $-1$ eigenspace of a Cartan involution), and these systems are totally controllable. However, finding a particular optimal trajectory can be in general a computationally difficult problem, and from an analytic perspective, the Lie groups are sufficiently complicated to make finding such objects as the cut locus difficult. $K-P ... Jan 2019 #### A Study Of Several Applications Of Parallel Computing In The Sciences Using Petsc, Nicholas Stegmeier ##### Electronic Theses and Dissertations The importance of computing in the natural sciences continues to grow as scientists strive to analyze complex phenomena. The dynamics of turbulence, astrophysics simulations, and climate change are just a few examples where computing is critical. These problems are computationally intractable on all computing platforms except supercomputers, necessitating the continued development of efficient algorithms and methodologies in parallel computing. This thesis investigates the use of parallel computing and mathematical modeling in the natural sciences through several applications, namely computational fluid dynamics for impinging jets in mechanical engineering, simulation of biofilms in an aqueous environment in mathematical biology, and the solution ... Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski Dec 2018 #### Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski ##### Wojciech Budzianowski No abstract provided. A Companion To The Introduction To Modern Dynamics, David D. Nolte Dec 2018 #### A Companion To The Introduction To Modern Dynamics, David D. Nolte ##### David D Nolte A Jr/Sr Mechanics/Dynamics textbook from Oxford University Press, updating how we teach undergraduate physics majors with increased relevance for physics careers in changing times. Additional materials, class notes and examples to go with the textbook Introduction to Modern Dynamics: Chaos, Networks, Space and Time (Oxford University Press, 2019). The best parts of physics are the last topics that our students ever see. These are the exciting new frontiers of nonlinear and complex systems that are at the forefront of university research and are the basis of many of our high-tech businesses. Topics such as traffic on the World ... Oct 2018 #### Predicted Deepwater Bathymetry From Satellite Altimetry: Non-Fourier Transform Alternatives, Maxsimo Salazar ##### Dissertations Robert Parker (1972) demonstrated the effectiveness of Fourier Transforms (FT) to compute gravitational potential anomalies caused by uneven, non-uniform layers of material. This important calculation relates the gravitational potential anomaly to sea-floor topography. As outlined by Sandwell and Smith (1997), a six-step procedure, utilizing the FT, then demonstrated how satellite altimetry measurements of marine geoid height are inverted into seafloor topography. However, FTs are not local in space and produce Gibb’s phenomenon around discontinuities. Seafloor features exhibit spatial locality and features such as seamounts and ridges often have sharp inclines. Initial tests compared the windowed-FT to wavelets in reconstruction ... #### Attosecond Light Pulses And Attosecond Electron Dynamics Probed Using Angle-Resolved Photoelectron Spectroscopy, Cong Chen ##### Physics Graduate Theses & Dissertations Recent advances in the generation and control of attosecond light pulses have opened up new opportunities for the real-time observation of sub-femtosecond (1 fs = 10-15 s) electron dynamics in gases and solids. Combining attosecond light pulses with angle-resolved photoelectron spectroscopy (atto-ARPES) provides a powerful new technique to study the influence of material band structure on attosecond electron dynamics in materials. Electron dynamics that are only now accessible include the lifetime of far-above-bandgap excited electronic states, as well as fundamental electron interactions such as scattering and screening. In addition, the same atto-ARPES technique can also be used to measure the ... Aug 2018 #### Topological Recursion And Random Finite Noncommutative Geometries, Shahab Azarfar ##### Electronic Thesis and Dissertation Repository In this thesis, we investigate a model for quantum gravity on finite noncommutative spaces using the topological recursion method originated from random matrix theory. More precisely, we consider a particular type of finite noncommutative geometries, in the sense of Connes, called spectral triples of type${(1,0)} \,$, introduced by Barrett. A random spectral triple of type${(1,0)}$has a fixed fermion space, and the moduli space of its Dirac operator${D=\{ H , \cdot \} \, ,}{H \in {\mathcal{H}_N}}$, encoding all the possible geometries over the fermion space, is the space of Hermitian matrices${\mathcal{H}_N}\$. A distribution of ...

Topics In Pt-Symmetric Quantum Mechanics And Classical Systems, Nima Hassanpour Aug 2018

#### Topics In Pt-Symmetric Quantum Mechanics And Classical Systems, Nima Hassanpour

##### Arts & Sciences Electronic Theses and Dissertations

Space-time reflection symmetry, or PT symmetry, first proposed in quantum mechanics by Bender and Boettcher in 1998 [2], has become an active research area in fundamental physics. This dissertation contains several research problems which are more or less related to this field of study. After an introduction on complementary topics for the main projects in Chap.1, we discuss about an idea which is originated from the remarkable paper by Chandrasekar et al in Chap.2. They showed that the (second-order constant-coefficient) classical equation of motion for a damped harmonic oscillator can be derived from a Hamiltonian having one degree ...

Aug 2018

#### Internal And External Harmonic Functions In Flat-Ring Coordinates, Lijuan Bi

##### Theses and Dissertations

The goal of this dissertation is to derive expansions for a fundamental solution of Laplace's equation in flat-ring coordinates in three-dimensional Euclidean space. These expansions are in terms of harmonic functions in the interior and the exterior of two different types of regions, "flat rings" and "peanuts" according to their shapes. We solve Laplace's equation in the interior and the exterior of these regions using the method of separation of variables. The internal and external "flat-ring" and "peanut" harmonic functions are expressed in terms of Lamé functions.

Generalized Fock Spaces And The Stirling Numbers, Daniel Alpay, Motke Porat Jun 2018

#### Generalized Fock Spaces And The Stirling Numbers, Daniel Alpay, Motke Porat

##### Mathematics, Physics, and Computer Science Faculty Articles and Research

The Bargmann-Fock-Segal space plays an important role in mathematical physics and has been extended into a number of directions. In the present paper, we imbed this space into a Gelfand triple. The spaces forming the Fréchet part (i.e., the space of test functions) of the triple are characterized both in a geometric way and in terms of the adjoint of multiplication by the complex variable, using the Stirling numbers of the second kind. The dual of the space of test functions has a topological algebra structure, of the kind introduced and studied by the first named author and Salomon.

Full Dyon Excitation Spectrum In Extended Levin-Wen Models, Yuting Hu, Nathan Geer, Yong-Shi Wu May 2018

#### Full Dyon Excitation Spectrum In Extended Levin-Wen Models, Yuting Hu, Nathan Geer, Yong-Shi Wu

##### Mathematics and Statistics Faculty Publications

In Levin-Wen (LW) models, a wide class of exactly solvable discrete models, for two-dimensional topological phases, it is relatively easy to describe only single-fluxon excitations, but not the charge and dyonic as well as many-fluxon excitations. To incorporate charged and dyonic excitations in (doubled) topological phases, an extension of the LW models is proposed in this paper. We first enlarge the Hilbert space with adding a tail on one of the edges of each trivalent vertex to describe the internal charge degrees of freedom at the vertex. Then, we study the full dyon spectrum of the extended LW models, including ...

May 2018

#### The Advection-Diffusion Equation And The Enhanced Dissipation Effect For Flows Generated By Hamiltonians, Michael Kumaresan

##### All Dissertations, Theses, and Capstone Projects

We study the Cauchy problem for the advection-diffusion equation when the diffusive parameter is vanishingly small. We consider two cases - when the underlying flow is a shear flow, and when the underlying flow is generated by a Hamiltonian. For the former, we examine the problem on a bounded domain in two spatial variables with Dirichlet boundary conditions. After quantizing the system via the Fourier transform in the first spatial variable, we establish the enhanced-dissipation effect for each mode. For the latter, we allow for non-degenerate critical points and represent the orbits by points on a Reeb graph, with vertices representing ...