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Full-Text Articles in Physics
Spin Systems On Hierarchical Lattices. Introduction And Thermodynamic Limit, Robert B. Griffiths, Miron Kaufman
Spin Systems On Hierarchical Lattices. Introduction And Thermodynamic Limit, Robert B. Griffiths, Miron Kaufman
Miron Kaufman
A number of exactly soluble models in statistical mechanics can be produced with the use of spins interacting with nearest neighbors on a hierarchical lattice. A general definition and several examples of such lattices are given, and the topological properties of one of these, the "diamond" lattice, are discussed in detail. It is shown that the free energy has a well-defined thermodynamic limit for a large class of discrete spin models on hierarchical lattices.
First-Order Transitions In Defect Structures At A Second-Order Critical Point, Miron Kaufman, Robert B. Griffiths
First-Order Transitions In Defect Structures At A Second-Order Critical Point, Miron Kaufman, Robert B. Griffiths
Miron Kaufman
On certain hierarchical lattices the order parameter on a defect line increases discontinuously at the bulk critical temperature for q-state Potts models when q is sufficiently large, even though the bulk order parameter increases continuously. It is suggested that the same behavior may occur for two-dimensional lattices with 2 < q <= 4.
Long Wavelength Irregularities In The Equatorial Electrojet, E. Kudeki, D. T. Farley, Bela G. Fejer
Long Wavelength Irregularities In The Equatorial Electrojet, E. Kudeki, D. T. Farley, Bela G. Fejer
Bela G. Fejer
We have used the radar interferometer technique at Jicamarca to study in detail irregularities with wavelengths of a few kilometers generated in the unstable equatorial electrojet plasma during strong type 1 conditions. In-situ rocket observations of the same instability process are discussed in a companion paper. These large scale primary waves travel essentially horizontally and have large amplitudes. The vertical electron drift velocities driven by the horizontal wave electric fields reach or exceed the ion-acoustic velocity even though the horizontal phase velocity of the wave is considerably smaller. A straightforward extension to the long wavelength regime of the usual linear …
In-Situ Measurements Ofwave Electric Fields In The Equatorial Electrojet, R. C. Pfaff, M. C. Kelley, Bela G. Fejer, N. C. Maynard, K. D. Baker
In-Situ Measurements Ofwave Electric Fields In The Equatorial Electrojet, R. C. Pfaff, M. C. Kelley, Bela G. Fejer, N. C. Maynard, K. D. Baker
Bela G. Fejer
Electric field wave measurements have been performed on two sounding rockets in the equatorial ionosphere. During a daytime flight from Chilca, Peru, intense electrostatic waves were detected on the upward directed electron density gradient. During a nighttime flight from Kwajalein Atoll, similar waves were detected on a downward directed gradient. These results are in agreement with a gradient drift instability explanation of the generation of the waves. The wave amplitudes were as high as 5 mV/m implying perturbation drifts comparable to the driving drift velocities. Power spectra from the turbulent region show a peak at long wavelengths, followed by a …
Electro-Optics Applications For Alleviating Emi/Emc/Emp Problems, George H. Baker, Walter H. Hardwick
Electro-Optics Applications For Alleviating Emi/Emc/Emp Problems, George H. Baker, Walter H. Hardwick
George H Baker
No abstract provided.
Structure-Factor Measurements In 4he As A Function Of Density, Robert Hallock, H. N. Robkoff
Structure-Factor Measurements In 4he As A Function Of Density, Robert Hallock, H. N. Robkoff
Robert Hallock
Measurements of the structure factor S(k) for 4He are reported as a function of pressure at 1.67, 2.20, and 4.24 K from saturated vapor pressure to 25 atm. The liquid structure factor is seen to sharpen and increase in amplitude with an increase in pressure at each of the temperatures studied. Comparison is made to previous results obtained by the technique of neutron scattering as well as to the theoretical predictions of Chang and Campbell and of Whitlock et al. The pair correlation function g(r) is obtained from the liquid structure factor by means of a Fourier transform, and comparison …
Thermodynamic Model For Tricritical Mixtures With Application To Ammonium, Miron Kaufman, Robert B. Griffiths
Thermodynamic Model For Tricritical Mixtures With Application To Ammonium, Miron Kaufman, Robert B. Griffiths
Miron Kaufman
Procedures are developed for using composition data in the three-phase region and variations of meniscus heights to determine the parameters needed to relate a classical thermodynamic model for fluid mixtures near tricritical points to actual experiments. In the case of the mixture ammonium sulfate + water + ethanol + benzene the result is a reasonably good fit to a variety of data, including light scattering measurements of intensity and correlation length. There is some evidence for deviations from the classical theory, but it is not unambiguous.
Infinite Susceptibility At High Temperatures In The Migdal-Kadanoff Scheme, Miron Kaufman, Robert B. Griffiths
Infinite Susceptibility At High Temperatures In The Migdal-Kadanoff Scheme, Miron Kaufman, Robert B. Griffiths
Miron Kaufman
The Migdal-Kadanoff real-space renormalisation group scheme applied to the Ising and classical XY (and probably other) ferromagnetic models yields an infinite susceptibility at all temperatures above the critical temperature for a hypercubic lattice of dimension d > 2.
Y Expansion For Directed Lattice Animals, Anthony Day, T. Lubensky
Y Expansion For Directed Lattice Animals, Anthony Day, T. Lubensky
Anthony Roy Day
No abstract provided.
Path-Integrals And The Wkb Approximation, Br Holstein, Ar Swift
Path-Integrals And The Wkb Approximation, Br Holstein, Ar Swift
Barry R Holstein
The WKB approximation is demonstrated to be formally identical to the semiclassical limit of the Feynman path integral propagator. In the limit that the path integral propagator is dominated by the classical particle trajectory, it is identical to the propagator calculated directly from WKB wave functions in the stationary phase approximation.