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Articles 1 - 30 of 33
Full-Text Articles in Physics
The Coefficient Of Bohm Diffusion In Fully Ionized Plasma And Its Theoretical Proof, Ahmad Talaei, Reza Amrollahi
The Coefficient Of Bohm Diffusion In Fully Ionized Plasma And Its Theoretical Proof, Ahmad Talaei, Reza Amrollahi
Graduate Student Presentations
As we know, the classical diffusion can not be able to respond the experimental results of the diffusion in the fully ionized and isothermal plasma. In this article, we purpose to extract the empirical coefficients of the Bohm diffusion and its confinement time, theoretically, in the fully ionized plasma, using the single fluid MHD equations.
Mesospheric Gravity Waves Observed Near Equatorial And Low-Middle Latitude Stations: Wave Characteristics And Reverse Ray Tracing Results, C. M. Wrasse, T. Nakamura, H. Takahshi, A. F. Medeiros, Michael J. Taylor, D. Gobi, C. M. Denardini, J. Fechine, R. A. Buriti, A. Salatun, Suratno, E. Achmad, A. G. Admiranto
Mesospheric Gravity Waves Observed Near Equatorial And Low-Middle Latitude Stations: Wave Characteristics And Reverse Ray Tracing Results, C. M. Wrasse, T. Nakamura, H. Takahshi, A. F. Medeiros, Michael J. Taylor, D. Gobi, C. M. Denardini, J. Fechine, R. A. Buriti, A. Salatun, Suratno, E. Achmad, A. G. Admiranto
All Physics Faculty Publications
Gravity wave signatures were extracted from OH airglow observations using all-sky CCD imagers at four different stations: Cachoeira Paulista (CP) (22.7° S, 45° W) and São João do Cariri (7.4° S, 36.5° W), Brazil; Tanjungsari (TJS) (6.9° S, 107.9° E), Indonesia and Shigaraki (34.9° N, 136° E), Japan. The gravity wave parameters are used as an input in a reverse ray tracing model to study the gravity wave vertical propagation trajectory and to estimate the wave source region. Gravity waves observed near the equator showed a shorter period and a larger phase velocity than those waves observed at low-middle latitudes. …
Methods For High Resistivity Measurements Related To Spacecraft Charging, Jr Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A Robb Frederickson
Methods For High Resistivity Measurements Related To Spacecraft Charging, Jr Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A Robb Frederickson
Journal Articles
A key parameter in modeling differential spacecraft charging is the resistivity of insulating materials. This parameter determines how charge will accumulate and redistribute across the spacecraft, as well as the time scale for charge transport and dissipation. ASTM constant voltage methods are shown to provide inaccurate resistivity measurements for materials with resistivities greater than ~1017 Ω-cm or with long polarization decay times such as are found in many polymers. These data have been shown to often be inappropriate for spacecraft charging applications, and have been found to underestimate charging effects by one to four orders of magnitude for many …
Response To Earl Wunderli's Critique Of Alma 36 As An Extended Chiasm, Boyd F. Edwards, W. F. Edwards
Response To Earl Wunderli's Critique Of Alma 36 As An Extended Chiasm, Boyd F. Edwards, W. F. Edwards
All Physics Faculty Publications
No abstract provided.
Propagation Velocities Of Chemical Reaction Fronts Advected By Poiseuille Flow, Boyd F. Edwards
Propagation Velocities Of Chemical Reaction Fronts Advected By Poiseuille Flow, Boyd F. Edwards
All Physics Faculty Publications
Poiseuille flow between parallel plates advects chemical reaction fronts, distorting them and altering their propagation velocities. Analytical solutions of the cubic reaction-diffusion-advection equation resolve the chemical concentration for narrow gaps, wide gaps, and small-amplitude flow. Numerical solutions supply a general description for fluid flow in the direction of propagation of the chemical reaction front, and for flow in the opposite direction. Empirical relations for the velocity agree with numerical solutions to within a few percent, and agree exactly with the analytical limits. Applications to nonlinear fingering are discussed.
Methods For Resistivity Measurements Related To Spacecraft Charging, John R. Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A. Robb Frederickson
Methods For Resistivity Measurements Related To Spacecraft Charging, John R. Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A. Robb Frederickson
All Physics Faculty Publications
A key parameter in modeling differential spacecraft-charging is the resistivity of insulating materials. This parameter determines how charge will accumulate and redistribute across the spacecraft, as well as the timescale for charge transport and dissipation. American Society for Testing and Materials constant-voltage methods are shown to provide inaccurate resistivity measurements for materials with resistivities greater than ~1017 Omegamiddotcm or with long polarization decay times such as are found in many polymers. These data have been shown to often be inappropriate for spacecraft-charging applications and have been found to underestimate charging effects by one to four orders of magnitude for …
Evolution Of The Electron Yield Curves Of Insulators As A Function Of Impinging Electron Fluence And Energy, John R. Dennison, Alec Sim, Clint Thomson
Evolution Of The Electron Yield Curves Of Insulators As A Function Of Impinging Electron Fluence And Energy, John R. Dennison, Alec Sim, Clint Thomson
All Physics Faculty Publications
Electron emission and concomitant charge accumulation near the surface of insulators is central to understanding spacecraft charging. A study of changes in electron emission yields as a result of internal charge buildup due to electron dose is presented. Evolution of total, backscattered, and secondary yield results over a broad range of incident energies are presented for two representative insulators, Kapton and Al2O3. Reliable yield curves for uncharged insulators are measured, and quantifiable changes in yields are observed due to <100-fC/mm2 fluences. Excellent agreement with a phenomenological argument based on insulator charging predicted by the yield curve …
Experimentally Derived Resistivity For Dielectric Samples From The Crres Internal Discharge Monitor, Nelson W. Green, A. Robb Frederickson, John R. Dennison
Experimentally Derived Resistivity For Dielectric Samples From The Crres Internal Discharge Monitor, Nelson W. Green, A. Robb Frederickson, John R. Dennison
All Physics Faculty Publications
Resistivity values were experimentally determined using charge-storage methods for six samples remaining from the construction of the internal discharge monitor flown on the Combined Release and Radiation Effects Satellite (CRRES). Three tests were performed over a period of three to five weeks each in a vacuum of ~5times10-6 torr with an average temperature of ~25degC to simulate a space environment. Samples tested included FR4, polytetrafluoroethylene (PTFE), and alumina with copper electrodes attached to one or more of the sample surfaces. FR4 circuit-board material was found to have a dark-current resistivity of ~1times1018 Omegamiddotcm and a moderately high polarization …
On The Computation Of Secondary Electron Emission Models, Sebastien Clerc, John R. Dennison, Ryan Hoffmann, Jonathon Abbott
On The Computation Of Secondary Electron Emission Models, Sebastien Clerc, John R. Dennison, Ryan Hoffmann, Jonathon Abbott
All Physics Faculty Publications
Secondary electron emission is a critical contributor to the charge particle current balance in spacecraft charging. Spacecraft charging simulation codes use a parameterized expression for the secondary electron (SE) yield delta(Eo) as a function of the incident electron energy Eo. Simple three-step physics models of the electron penetration, transport, and emission from a solid are typically expressed in terms of the incident electron penetration depth at normal incidence R(Eo) and the mean free path of the SE lambda. In this paper, the authors recall classical models for the range R(Eo): a power …
Does Joseph's Letter To Emma Of 4 November 1838 Show That He Knew About Chiasmus?, Boyd F. Edwards, W. F. Edwards
Does Joseph's Letter To Emma Of 4 November 1838 Show That He Knew About Chiasmus?, Boyd F. Edwards, W. F. Edwards
All Physics Faculty Publications
No abstract provided.
Secondary Electron Production And Transport Mechanisms By Measurement Of Angle-Energy Resolved Cross Sections Of Secondary And Backscattered Electron Emission From Gold, Jason T. Kite
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This work provides information about interactions that produce emitted electrons from polycrystalline Au. Emission energy- angle- dependent electron spectra from a polycrystalline Au surface have been measured at several incident electron beam energies. The range of incident energies (~100 eV to 2500 eV) extends from below the first crossover energy, through Emaxo, to above the second crossover energy. The conventional distinction between secondary electrons (SE) (<50 eV) is found to be crude for the investigation of electron yields using these energy- angle- resolved measurements. A more realistic boundary occurs at the local minima of the emission spectra; this feature is studied as a function of incident energy and emission angle. In addition, deviations observed in the angular resolved emission spectra from isotropic behavior suggests that residual signatures exist in the emission spectra resulting from the anisotropic SE production mechanisms. Based on the disparity between our observations and recent modeling of the emission spectra, the most recent theory and simulation studies may overestimate the occurrence of randomizing collisions of scattered secondary electrons in the model of the transport mechanism. Finally, description of extensive modification to instrumental and analysis methods are described, and their effectiveness is evaluated.
Response To Earl Wunderli’S "Critique Of Alma 36 As An Extended Chiasm”, Boyd F. Edwards, W. Farrell Edwards
Response To Earl Wunderli’S "Critique Of Alma 36 As An Extended Chiasm”, Boyd F. Edwards, W. Farrell Edwards
All Physics Faculty Publications
In his “Critique of Alma 36 as an Extended Chiasm,” Earl Wunderli argues that the chiastic structure of Alma 36, which was first published in 1969 by John W. Welch, was not in tended by the author of Alma 36. Wunderli also dismisses our recent statistical calculations, which indicate that the chiastic structure of Alma 36 is likely to be intentional. The purpose of this statement is to respond to Wunderli’s critique.
An Unusual Mesospheric Bore Event Observed At High Latitudes Over Antarctica, K. Nielsen, Michael J. Taylor, R G. Stockwell, M. J. Jarvis
An Unusual Mesospheric Bore Event Observed At High Latitudes Over Antarctica, K. Nielsen, Michael J. Taylor, R G. Stockwell, M. J. Jarvis
All Physics Faculty Publications
All-sky CCD observations of short-period mesospheric gravity waves have been made from Halley Station, Antarctica (76S, 27W). On 27 May, 2001, an unusual wave event exhibiting several features characteristic of a ‘‘bore’’ was observed in the OH, Na, and O2 nightglow emissions. Mesospheric bores are rare wave events that have previously been observed at mid- and low-latitudes. This event was particular interesting as: (1) it initially appeared as a single, high contrast, linear front, accompanied by a sharp enhancement in intensity in all three emissions, (2) a number of trailing wave crests were observed to form with a measured growth …
A Novel Joint Space-Wavenumber Analysis Of An Unusual Antarctic Gravity Wave Event, R. G. Stockwell, Michael J. Taylor, K. Nielsen, M. J. Jarvis
A Novel Joint Space-Wavenumber Analysis Of An Unusual Antarctic Gravity Wave Event, R. G. Stockwell, Michael J. Taylor, K. Nielsen, M. J. Jarvis
All Physics Faculty Publications
As part of a collaborative research program between British Antarctic Survey, U.K. and Utah State University, USA, all sky airglow images were recorded at Halley Station Antarctica (75.5 S, 26.7 W). An unusual mesospheric gravity wave event was observed in the OH nightglow (nominal height 87 km) over a period of 3 hours on the 27–28 May, 2001. The characteristics of the bore wave event were determined by application of the one dimensional spatial S-Transform analysis. This is the first time such analysis has been performed on airglow data. By employing these local spatial spectral analysis, the evolution of the …
Seasonal Variation Of Diurnal Perturbations In Mesopause Regiontemperature, Zonal, And Meridional Winds Above Fort Collins, Colorado (40.6°N, 105°), Tao Yuan, C. Y. She, M. E. Hagan, B. P. William, T. Li, K. Arnold, T. D. Kawahara, P. E. Acott, J. D. Vance, D. A. Krueger, R. G. Roble
Seasonal Variation Of Diurnal Perturbations In Mesopause Regiontemperature, Zonal, And Meridional Winds Above Fort Collins, Colorado (40.6°N, 105°), Tao Yuan, C. Y. She, M. E. Hagan, B. P. William, T. Li, K. Arnold, T. D. Kawahara, P. E. Acott, J. D. Vance, D. A. Krueger, R. G. Roble
All Physics Faculty Publications
On the basis of lidar observations from May 2002 through April 2003, covering both day and night, we performed a harmonic analysis to extract the diurnal perturbations in mesopause region temperature, zonal and meridional winds over Fort Collins, Colorado (40.6°N, 105°W), binned every 2 months. The results were compared to predictions of the 2000 and 2002 versions of Global-Scale Wave Model (GSWM00 and GSWM02). The diurnal tidal period oscillations showed a mixture of propagating and evanescent (trapped) modes, but the propagating modes dominated for most of the year. The agreement in temperature diurnal phases between observation and GSWM prediction is …
Evolution Of Equatorial Ionospheric Bubbles During A Large Auroral Electrojet Increase In The Recovery Phase Of A Magnetic Storm, M. J. Keskinen, S. L. Ossakow, Bela G. Fejer, J. Emmert
Evolution Of Equatorial Ionospheric Bubbles During A Large Auroral Electrojet Increase In The Recovery Phase Of A Magnetic Storm, M. J. Keskinen, S. L. Ossakow, Bela G. Fejer, J. Emmert
Bela G. Fejer
[1] We present a model and observations of the evolution of equatorial ionospheric bubbles during a large auroral electrojet (AE) index increase in the recovery phase of a geomagnetic storm. Using a three-dimensional time-dependent numerical simulation model, we find, for the 19–21 October 1998 storm, that the equatorial bubble evolution is different during storm time as compared to quiet time conditions. We have found that the storm time vertical drift in conjunction with reduced off-equatorial E region shorting is the primary mechanism that distinguishes the large AE increase recovery phase storm time evolution from the quiet time case. Comparison of …
Electron Transport In Laterally Confined Phosphorus Δ-Layers In Silicon, S. J. Robinson, J. S. Kline, H. J. Wheelwright, J. R. Tucker, C. L. Yang, R. R. Du, B. E. Volland, I. W. Rangelow, T. -C. Shen
Electron Transport In Laterally Confined Phosphorus Δ-Layers In Silicon, S. J. Robinson, J. S. Kline, H. J. Wheelwright, J. R. Tucker, C. L. Yang, R. R. Du, B. E. Volland, I. W. Rangelow, T. -C. Shen
T. -C. Shen
Two-dimensional electron systems fabricated from a single layer of P-donors have been lithographically confined to nanometer scale in lateral directions. The electronic transport of such quasi-one-dimensional systems with and without a perpendicular magnetic field was characterized at cryogenic temperatures. Experimental data fit well with two-dimensional weak localization and interaction theory when the phase coherence length is shorter than the smaller dimension of the confinement. Below a transition temperature the wire conductance saturates.
Design And Construction Of A Misse-6 Payload: State Of Utah Space Environment & Contamination Study (Suspecs), Joshua L. Hodges, Jeff Duce, John R. Dennison
Design And Construction Of A Misse-6 Payload: State Of Utah Space Environment & Contamination Study (Suspecs), Joshua L. Hodges, Jeff Duce, John R. Dennison
All Physics Faculty Publications
No abstract provided.
Suspects- State Of Utah Space, Environment & Contamnation Study- Misse Vi, Jeff Ducea, Josh Hodgesa, Jacob Geddesa, Andrew Aumana, Sarah Bartona, Jr Dennison, Clint Thomsonc, J. W. Burnsc, L. Pearsonc, L. Davis, R. S. Hydec, James S. Dyerd
Suspects- State Of Utah Space, Environment & Contamnation Study- Misse Vi, Jeff Ducea, Josh Hodgesa, Jacob Geddesa, Andrew Aumana, Sarah Bartona, Jr Dennison, Clint Thomsonc, J. W. Burnsc, L. Pearsonc, L. Davis, R. S. Hydec, James S. Dyerd
Posters
A Study of the effects of prolonged exposure to the space environment and of charge-enhanced contamination on the electron emission and resistivity of spacecraft materials, the State of Utah Space Environment & Contamination Study (SUSpECTS), is planned for flight aboard the MISSE-6 payload. the Materials International Space month exposure periods on-orbit on the International Space Station, with a target flight date of mid-2006. The study is conducted by the Utah State University Materials that contamination can lead to catastrophic charging effects under certain circumstances, little direct information is presently available on the effects of sample deterioration and on emission properties …
Gravitational Waves: Just Plane Symmetry, Charles G. Torre
Gravitational Waves: Just Plane Symmetry, Charles G. Torre
All Physics Faculty Publications
In four spacetime dimensions gravitational plane waves (a special case of the plane-fronted waves with parallel rays) admit a 5 parameter isometry group. We generalize this group to n-dimensions and explore some special features of spacetimes admitting this isometry group. In particular, it is shown that every generally covariant rank-2 symmetric tensor field constructed from a metric with plane wave symmetry will vanish except multiples of the metric and Ricci tensors. We show that, in four spacetime dimensions, a particular enlargement of the plane wave symmetry group is enough to force the group-invariant metrics to satisfy all generally covariant vacuum …
Validation Study Of The Ionospheric Forecast Model Using The Topex Tec Measurements, L. Zhu, Robert W. Schunk, G. Jee, Ludger Scherliess, Jan Josef Sojka, Donald C. Thompson
Validation Study Of The Ionospheric Forecast Model Using The Topex Tec Measurements, L. Zhu, Robert W. Schunk, G. Jee, Ludger Scherliess, Jan Josef Sojka, Donald C. Thompson
All Physics Faculty Publications
As a part of the validation program in the Utah State University Global Assimilation of Ionospheric Measurement (GAIM) project, a newly improved Ionosphere Forecast Model (IFM) was systematically validated by using a large database of TOPEX total electron content (TEC) measurements. The TOPEX data used for the validation are for the period from August 1992 to March 2003, and the total number of 18-s averaged data is close to 11 million. This model validation work covers a wide range of seasonal (winter, summer, and equinox) and solar (low-F 10.7, median F 10.7, and high-F 10.7) conditions as well as all …
Utah State University Global Assimilation Of Ionospheric Measurements Gauss-Markov Kalman Filter Model Of The Ionosphere: Model Description And Validation, Ludger Scherliess, Robert W. Schunk, Jan Josef Sojka, Donald C. Thompson, Lie Zhu
Utah State University Global Assimilation Of Ionospheric Measurements Gauss-Markov Kalman Filter Model Of The Ionosphere: Model Description And Validation, Ludger Scherliess, Robert W. Schunk, Jan Josef Sojka, Donald C. Thompson, Lie Zhu
All Physics Faculty Publications
The Utah State University Gauss-Markov Kalman Filter (GMKF) was developed as part of the Global Assimilation of Ionospheric Measurements (GAIM) program. The GMKF uses a physics-based model of the ionosphere and a Gauss-Markov Kalman filter as a basis for assimilating a diverse set of real-time (or near real-time) observations. The physics-based model is the Ionospheric Forecast Model (IFM), which accounts for five ion species and covers the E region, F region, and the topside from 90 to 1400 km altitude. Within the GMKF, the IFM derived ionospheric densities constitute a background density field on which perturbations are superimposed based on …
Wavelet-Based Index Of Magnetic Storm Activity, A. Jach, Piotr Kokoszka, Jan Josef Sojka, Lie Zhu
Wavelet-Based Index Of Magnetic Storm Activity, A. Jach, Piotr Kokoszka, Jan Josef Sojka, Lie Zhu
All Physics Faculty Publications
A wavelet-based method of computing an index of storm activity is put forward. The new index can be computed automatically using statistical procedures and does not require selecting quiet days and removing the secular component by polynomial fitting. This 1-min index is designed to facilitate the study of the fine structure of geomagnetic storm events and requires only the most recent magnetogram records, e.g., the 2 months including the storm event of interest. It can thus be computed over a moving window as soon as new magnetogram records become available. Averaged over 1-hour periods, it is practically indistinguishable from the …
Probability Tails Of Wavelet Coefficients Of Magnetometer Records, Piotr Kokoszka, I. Maslova, Jan Josef Sojka, Lie Zhu
Probability Tails Of Wavelet Coefficients Of Magnetometer Records, Piotr Kokoszka, I. Maslova, Jan Josef Sojka, Lie Zhu
All Physics Faculty Publications
The ground-based magnetometer network has long been a powerful tool for monitoring and observing the variations of the currents flowing in the magnetosphere-ionosphere (M-I) system. The time series of magnetograms are nonstationary and their frequency behavior changes over time. They are therefore not amenable to traditional time domain or spectral (Fourier) analysis. In recent years, various new mathematical techniques have been developed to analyze magnetometer data and the wavelet technique has stood out as being particularly relevant. In order to correctly make statistical inferences based on wavelet analysis, the wavelet coefficient distributions of magnetograms must be examined. In this work, …
Anomalous F Region Response To Moderate Solar Flares, C. G. Smithtro, Jan Josef Sojka, T. Berkey, Donald C. Thompson, Robert W. Schunk
Anomalous F Region Response To Moderate Solar Flares, C. G. Smithtro, Jan Josef Sojka, T. Berkey, Donald C. Thompson, Robert W. Schunk
All Physics Faculty Publications
Ionograms recorded with a dynasonde at Bear Lake Observatory, Utah, during moderate solar x-ray flares exhibit characteristic enhancements to the E and F 1 region ionosphere. However, during these same flares, the peak electron density of the ionosphere (N m F 2) unexpectedly decreases, recovering after the flare ends. In order to reconcile this anomalous behavior with expected increases to the total electron content (TEC), we undertake a modeling effort using the Time-Dependent Ionospheric Model (TDIM) developed at Utah State University. For solar input, a simple flare time irradiance model is created, using measurements from the Solar EUV Experiment instrument …
Extreme Longitudinal Variability Of Plasma Structuring In The Equatorial Ionosphere On A Magnetically Quiet Equinoctial Day, Sarah E. Mcdonald, Sunanda Basu, Santimay Basu, Keith M. Groves, Cesar E. Valladares, Ludger Scherliess, Donald C. Thompson, Robert W. Schunk, Jan Josef Sojka
Extreme Longitudinal Variability Of Plasma Structuring In The Equatorial Ionosphere On A Magnetically Quiet Equinoctial Day, Sarah E. Mcdonald, Sunanda Basu, Santimay Basu, Keith M. Groves, Cesar E. Valladares, Ludger Scherliess, Donald C. Thompson, Robert W. Schunk, Jan Josef Sojka
All Physics Faculty Publications
We investigate the extreme longitudinal variability of equatorial scintillation under quiet magnetic conditions during 22–23 March 2002. Scintillation Network Decision Aid (SCINDA) observations show intense activity in the South American–Atlantic sector during local evening hours, whereas an absence of scintillation is seen in the far east Asian sector. Ground- and space-based measurements from SCINDA, the Global Ultraviolet Imager (GUVI), TOPEX, and a chain of GPS receivers are used in combination with the Utah State University Global Assimilation of Ionospheric Measurements (USU-GAIM) model to explore the relationship between the large-scale ionization distribution and small-scale irregularities at low latitudes in both the …
Biconformal Matter Actions, A. Wehner, James Thomas Wheeler
Biconformal Matter Actions, A. Wehner, James Thomas Wheeler
All Physics Faculty Publications
We extend 2n-dim biconformal gauge theory by including Lorentz-scalar matter fields of arbitrary conformal weight. We show that for a massless scalar field of conformal weight zero in a torsion-free biconformal geometry, the solution is determined by the Einstein equation on an n-dim submanifold, with the stress-energy tensor of the scalar field as source. The matter field satisfies the n-dim Klein-Gordon equation.
Science Icebreaker Activities: An Example From Gravitational Wave Astronomy, Michelle B. Larson, Louis J. Rubbo, Kristina D. Zaleski, Shane L. Larson
Science Icebreaker Activities: An Example From Gravitational Wave Astronomy, Michelle B. Larson, Louis J. Rubbo, Kristina D. Zaleski, Shane L. Larson
All Physics Faculty Publications
At the beginning of a class, workshop, or meeting, an icebreaker activity is often used to help loosen up the group and get everyone talking. When used as a precursor to group learning, the icebreaker fosters communication so later activities function more smoothly. Science-based icebreaker activities serve the purpose of a traditional icebreaker, while also introducing science content to the audience. The content of the icebreaker may or may not be related to the topic of the upcoming class or meeting. Either way, the activity provides a way to get people talking while the participants simultaneously learn something new and …
Observables For The Polarized Gowdy Model, Charles G. Torre
Observables For The Polarized Gowdy Model, Charles G. Torre
All Physics Faculty Publications
We give an explicit characterization of all functions on the phase space for the polarized Gowdy 3-torus spacetimes which have weakly vanishing Poisson brackets with the Hamiltonian and momentum constraint functions.
Uniqueness Of Solutions To The Helically Reduced Wave Equation With Sommerfeld Boundary Conditions, Charles G. Torre
Uniqueness Of Solutions To The Helically Reduced Wave Equation With Sommerfeld Boundary Conditions, Charles G. Torre
All Physics Faculty Publications
We consider the helical reduction of the wave equation with an arbitrary source on (n+1)-dimensional Minkowski space, n ≥ 2. The reduced equation is of mixed elliptic-hyperbolic type on Rn. We obtain a uniqueness theorem for solutions on a domain consisting of an n-dimensional ball B centered on the reduction of the axis of helical symmetry and satisfying ingoing or outgoing Sommerfeld conditions on ∂B ≈ Sn−1. Nonlinear generalizations of such boundary value problems (with n = 3) arise in the intermediate phase of binary inspiral in general relativity.