Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Elementary Particles and Fields and String Theory (4)
- Astrophysics and Astronomy (3)
- Quantum Physics (3)
- Other Astrophysics and Astronomy (2)
- Other Physics (2)
-
- Applied Mathematics (1)
- Atomic, Molecular and Optical Physics (1)
- Chemical Engineering (1)
- Cosmology, Relativity, and Gravity (1)
- Engineering (1)
- Environmental Sciences (1)
- Geometry and Topology (1)
- Heat Transfer, Combustion (1)
- Mathematics (1)
- Mechanical Engineering (1)
- Nuclear (1)
- Nuclear Engineering (1)
- Oil, Gas, and Energy (1)
- Physical Processes (1)
- Thermodynamics (1)
- Institution
- Publication
- Publication Type
Articles 1 - 15 of 15
Full-Text Articles in Physics
Complete Matching For Quasidistribution Functions In Large Momentum Effective Theory, Wei Wang, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu
Complete Matching For Quasidistribution Functions In Large Momentum Effective Theory, Wei Wang, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu
Physics Faculty Publications
We complete the procedure of extracting parton distribution functions (PDFs) using large momentum effective theory at leading power accuracy in the hadron momentum. We derive a general factorization formula for the quasi-PDFs in the presence of mixing and give the corresponding hard matching kernel at O(αs), both for the unpolarized and for the polarized quark and gluon quasi-PDFs. Our calculation is performed in a regularization-independent momentum subtraction scheme. The results allow us to match the nonperturbatively renormalized quasi-PDFs to normal PDFs in the presence of mixing and therefore can be used to extract flavor-singlet quark PDFs as well …
Octonionic Maxwell Equations, Ben Shaw
Octonionic Maxwell Equations, Ben Shaw
Physics Capstone Projects
An introduction to Quaternions and Octonions is given, and the Maxwell Equations are formulated in terms of each. The conventional, source-free relativistic theory of eight dimensional electromagnetism is introduced and examined. Similarly, the source-free Octonionic Maxwell Equations are developed, and it is shown that the seven dimensional electric and magnetic fields–pure Octonions–each admit plane wave solutions. An Octonionic Faraday tensor is constructed and compared with the conventional Faraday tensor, and it is shown that, in the source-free case, the conventional and Octonionic theories are equivalent.
Colliding Wind Binaries With Orbital Motion: Line Wind Formulation, Brendan O'Connor
Colliding Wind Binaries With Orbital Motion: Line Wind Formulation, Brendan O'Connor
Honors Theses
Stars lose mass in the form of supersonic winds. In a binary star system, these winds collide to produce shockwaves. Such stellar wind collisions are observed in many binary star systems. Due to the orbital motion of the system, a trailing spiral structure is produced. We present a solution method in the co- rotating frame of the stars, which allow us to consider steady state solutions. This requires the inclusion of Coriolis and centrifugal forces, including their effects on the pre-shock winds, for which we were restricted to orbital speed slower than wind speeds. We assume efficient post-shock cooling, which …
General Relativity And Differential Geometry, Harry Hausner
Partial Differential Equations, Nathaniel James Onnen
Partial Differential Equations, Nathaniel James Onnen
Honors Theses
This paper will discuss methods for solving many different partial differential equations, as well as real world applications in physics. We are interested in finding solutions to the wave and heat equations in one dimension, the wave equation in two dimensions, as well as a solution to Schrodinger’s equation. In order to do this, we will study different methods including Fourier series, Bessel functions, and Hermite polynomials. I will use these methods to derive solutions for the mentioned problems, as well as to produce visualizations for many of them.
Direct Observation Of Quark-Hadron Duality In The Free Neutron F2 Structure Function, I. Niculescu, G. Niculescu, W. Melnitchouk, J. Arrington, M. E. Christy, S. Kuhn
Direct Observation Of Quark-Hadron Duality In The Free Neutron F2 Structure Function, I. Niculescu, G. Niculescu, W. Melnitchouk, J. Arrington, M. E. Christy, S. Kuhn
Physics Faculty Publications
Using the recently published data from the BONuS(Barely Off-shell Nucleon Structure) experiment at Jefferson Lab, which utilized a spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F2 structure function. The data are used to reconstruct the lowest few (N = 2, 4, and 6) moments of F2 in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark-hadron duality holds locally …
Conformal Kernel For The Next-To-Leading-Order Bfkl Equation In 𝒩 = 4 Super Yang-Mills Theory, Ian Balitsky, Giovanni A. Chirilli
Conformal Kernel For The Next-To-Leading-Order Bfkl Equation In 𝒩 = 4 Super Yang-Mills Theory, Ian Balitsky, Giovanni A. Chirilli
Physics Faculty Publications
Using the requirement of Möbius invariance of 𝒩 = 4 super Yang-Mills amplitudes in the Regge limit, we restore the explicit form of the conformal next-to-leading-order Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel out of the eigenvalues known from the forward next-to-leading-order BFKL result.
Micromagnetics Of The Domain Wall Mobility In Permalloy Nanowires, Andrew Kunz
Micromagnetics Of The Domain Wall Mobility In Permalloy Nanowires, Andrew Kunz
Physics Faculty Research and Publications
The domain wall mobility in long permalloy nanowires with thicknesses of 2-20 nm and widths of 50-200 nm has been simulated. The domain wall is driven into motion by an external magnetic field and the average wall mobility is calculated after the wall has traveled 2.5 mum along the wire. The results were obtained using the three-dimensional dynamic Landau-Lifshitz equation. We find that the domain wall mobility decreases linearly up to the critical field called the Walker field. The decreasing wall mobility is related to the decrease in the dynamic domain wall length as the applied field is increased. The …
Numerical Methods For The Stochastic Landau-Lifshitz Navier-Stokes Equations, Alejandro Garcia, J. B. Bell, S. Williams
Numerical Methods For The Stochastic Landau-Lifshitz Navier-Stokes Equations, Alejandro Garcia, J. B. Bell, S. Williams
Faculty Publications
The Landau-Lifshitz Navier-Stokes (LLNS) equations incorporate thermal fluctuations into macroscopic hydrodynamics by using stochastic fluxes. This paper examines explicit Eulerian discretizations of the full LLNS equations. Several computational fluid dynamics approaches are considered (including MacCormack’s two-step Lax-Wendroff scheme and the piecewise parabolic method) and are found to give good results for the variance of momentum fluctuations. However, neither of these schemes accurately reproduces the fluctuations in energy or density. We introduce a conservative centered scheme with a third-order Runge-Kutta temporal integrator that does accurately produce fluctuations in density, energy, and momentum. A variety of numerical tests, including the random walk …
Numerical Methods For The Stochastic Landau-Lifshitz Navier-Stokes Equations, Alejandro Garcia, John B. Bell, Sarah Williams
Numerical Methods For The Stochastic Landau-Lifshitz Navier-Stokes Equations, Alejandro Garcia, John B. Bell, Sarah Williams
Alejandro Garcia
The Landau-Lifshitz Navier-Stokes (LLNS) equations incorporate thermal fluctuations into macroscopic hydrodynamics by using stochastic fluxes. This paper examines explicit Eulerian discretizations of the full LLNS equations. Several computational fluid dynamics approaches are considered (including MacCormack’s two-step Lax-Wendroff scheme and the piecewise parabolic method) and are found to give good results for the variance of momentum fluctuations. However, neither of these schemes accurately reproduces the fluctuations in energy or density. We introduce a conservative centered scheme with a third-order Runge-Kutta temporal integrator that does accurately produce fluctuations in density, energy, and momentum. A variety of numerical tests, including the random walk …
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Physics Faculty Publications
The small-𝔁 deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov (BK) equation for the evolution of color dipoles. In the next-to-leading order (NLO) the nonlinear equation gets contributions from quark and gluon loops. In this paper I calculate the quark-loop contribution to small-𝔁 evolution of Wilson lines in the NLO. It turns out that there are no new operators at the one-loop level—just as at the tree level, the high-energy scattering can be described in terms of Wilson lines. In addition, …
Simulating The Maximum Domain Wall Speed In A Magnetic Nanowire, Andrew Kunz
Simulating The Maximum Domain Wall Speed In A Magnetic Nanowire, Andrew Kunz
Physics Faculty Research and Publications
The dynamics of domain wall motion in permalloy nanowires have been simulated utilizing the Landau-Lifshitz-Gilbert (LLG) equation of motion. The simulation results are presented in terms of the domain wall speed for ranges of the Gilbert damping parameter alpha and nanowire width. The maximum domain wall speed is independent of alpha. The speed of the domain wall can be increased by increasing the nanowire width, but this lowers the critical field. For applied fields below the critical field, the wall moves uniformly along the wire and the speed of the wall increases with increases in the driving field. This behavior …
Development Of A Model For Induction Heating, Randy Clarksean, Yitung Chen
Development Of A Model For Induction Heating, Randy Clarksean, Yitung Chen
Fuels Campaign (TRP)
There are two coupled equations that must be solved in order to determine the power deposition. The numerical solution of these equations is needed in order to apply a source term within the energy equations. These equations have previously solved in FIDAP. That implementation used modified versions of the momentum and energy equations to provide a mechanism for the solution of two coupled equations. Currently, we want to solve for the induction heating field in addition to the flow field and the energy equation. In order to do this, a mechanism has to be defined within FIDAP to solve these …
Microphysical Approach To Nonequilibrium Dynamics Of Quantum Fields, Marcelo Gleiser, Rudnei O. Ramos
Microphysical Approach To Nonequilibrium Dynamics Of Quantum Fields, Marcelo Gleiser, Rudnei O. Ramos
Dartmouth Scholarship
We examine the nonequilibrium dynamics of a self-interacting λφ4 scalar field theory. Using a real time formulation of finite temperature field theory we derive, up to two loops and O(λ2), the effective equation of motion describing the approach to equilibrium. We present a detailed analysis of the approxi- mations used in order to obtain a Langevin-like equation of motion, in which the noise and dissipation terms associated with quantum fluctuations obey a fluctuation-dissipation relation. We show that, in general, the noise is colored (time-dependent) and multiplicative (couples nonlinearly to the field), even though it is still Gaussian distributed. The noise …
Pseudostable Bubbles, Marcelo Gleiser
Pseudostable Bubbles, Marcelo Gleiser
Dartmouth Scholarship
The evolution of spherically symmetric unstable scalar field configura- tions (“bubbles”) is examined for both symmetric (SDWP) and asymmet- ric (ADWP) double-well potentials. Bubbles with initial static energiesE0 ∼< Ecrit, where Ecrit is some critical value, shrink in a time scale deter- mined by their linear dimension, or “radius”. Bubbles with E0 ∼> Ecrit evolve into time-dependent, localized configurations which are very long-lived com- pared to characteristic time-scales in the models examined. The stability of these configurations is investigated and possible applications are briefly discussed.