1,031,497 research outputs found
Continuum Singularities of a Mean Field Theory of Collisions
Consider a complex energy for a -particle Hamiltonian and let
be any wave packet accounting for any channel flux. The time independent
mean field (TIMF) approximation of the inhomogeneous, linear equation
consists in replacing by a product or Slater
determinant of single particle states This results, under the
Schwinger variational principle, into self consistent TIMF equations
in single particle space. The method is a
generalization of the Hartree-Fock (HF) replacement of the -body homogeneous
linear equation by single particle HF diagonalizations
We show how, despite strong nonlinearities in this mean
field method, threshold singularities of the {\it inhomogeneous} TIMF equations
are linked to solutions of the {\it homogeneous} HF equations.Comment: 21 pages, 14 figure
Inconsistencies in the MIT bag model of hadrons
It is shown that what is commonly referred to as the MIT `bag' model of
hadrons is thermodynamically wrong: The adiabatic conditions between pressure
and temperature, and between pressure and volume imply the third, an adiabatic
relation between temperature and volume. Consequently, the bag model is
destitute of any predictive power since it reduces to a single adiabatic state.
The virial theorems proposed by the MIT group are shown to be the result of the
normal power density of states of a non-degenerate gas and not the exponential
density of states of the Hagedorn mass spectrum. A number of other elementary
misconceptions and inaccuracies are also pointed out.Comment: 9 page
Loosely bound hyperons in the SU(3) Skyrme model
Hyperon pairs bound in deuteron like states are obtained within the SU(3)
Skyrme model in agreement with general expectations from boson exchange models.
The central binding from the flavor symmetry breaking terms increases with the
strangeness contents of the interacting baryons whereas the kinetic non-linear
-model term fixes the spin and isospin of the bound pair. We give a
complete account of the interactions of octet baryons within the product
approximation to baryon number configurations.Comment: 35 pages REVTEX including 2 figs, with 3 further figs available on
request from [email protected] or from [email protected]
SI-94-TP3S2; STPHY-Th/94-
The C-metric as a colliding plane wave space-time
It is explicitly shown that part of the C-metric space-time inside the black
hole horizon may be interpreted as the interaction region of two colliding
plane waves with aligned linear polarization, provided the rotational
coordinate is replaced by a linear one. This is a one-parameter generalization
of the degenerate Ferrari-Ibanez solution in which the focussing singularity is
a Cauchy horizon rather than a curvature singularity.Comment: 6 pages. To appear in Classical and Quantum Gravit
Passive dual spin misalignment compensators
A combination dual-spin gyroscopically stabilized device is described having a spinning rotor and a non-spinning platform. Two substantially lossless mechanical resonators, resonant at the spin frequency, are orthogonally positioned on the platform for compensation for the disturbing torque acting on the platform due to rotor misalignment
Selection Wages and Discrimination
Applicants for any given job are more or less suited to fill it, and the firm will select the best among them. Increasing the wage offer attracts more applicants and makes it possible to raise the hiring standard and improve the productivity of the staff. Wages that optimize on the trade-off between the wage level and the productivity of the workforce are known as selection wages. As men react more strongly to wage differentials than females, the trade-off is more pronounced for men and a profit-maximizing firm will offer a higher wage for men than for women in equilibrium
Of Some Theoretical Significance: Implications of Casimir Effects
In his autobiography Casimir barely mentioned the Casimir effect, but
remarked that it is "of some theortical significance." We will describe some
aspects of Casimir effects that appear to be of particular significance now,
more than half a century after Casimir's famous paper
High fidelity imaging and high performance computing in nonlinear EIT
We show that nonlinear EIT provides images with well defined characteristics when smoothness of the image is used as a constraint in the reconstruction process. We use the gradient of the logarithm of resistivity as an effective measure of image smoothness, which has the advantage that resistivity and conductivity are treated with equal weight. We suggest that a measure of the fidelity of the image to the object requires the explicit definition and application of such a constraint. The algorithm is applied to the simulation of intra-ventricular haemorrhaging (IVH) in a simple head model. The results indicate that a 5% increase in the blood content of the ventricles would be easily detectable with the noise performance of contemporary instrumentation. The possible implementation of the algorithm in real time via high performance computing is discussed
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