1,388 research outputs found
Competition and mergers in airline networks / 1523
Includes bibliographical references (p. 25)
Manipulable Congestion Tolls
The recent literature on congestion pricing with large agents contains a remarkable inconsistency: though agents are large enough to recognize self-imposed congestion and exert market power over prices, they do not take into account the impact of their own actions on the magnitude of congestion tolls. When large agents are confronted with tolls derived under this parametric assumption but understand the rule used to generate them, the toll system will no longer guide the market to the social optimum. To address this problem, the present paper derives alternate, manipulable toll rules, which are designed to achieve the social optimum when agents anticipate the full impact of their actions on toll liabilities.Pigouvian taxes; Congestion tolls
Manipulable Congestion Tolls
The recent literature on congestion pricing with large agents contains a remarkable inconsistency: though agents are large enough to recognize self-imposed congestion and exert market power over prices, they do not take into account the impact of their own actions on the magnitude of congestion tolls. When large agents are confronted with tolls derived under this parametric assumption but understand the rule used to generate them, the toll system will no longer guide the market to the social optimum. To address this problem, the present paper derives alternate, manipulable toll rules, which are designed to achieve the social optimum when agents anticipate the full impact of their actions on toll liabilities
A unitary correlation operator method
The short range repulsion between nucleons is treated by a unitary
correlation operator which shifts the nucleons away from each other whenever
their uncorrelated positions are within the replusive core. By formulating the
correlation as a transformation of the relative distance between particle
pairs, general analytic expressions for the correlated wave functions and
correlated operators are given. The decomposition of correlated operators into
irreducible n-body operators is discussed. The one- and two-body-irreducible
parts are worked out explicitly and the contribution of three-body correlations
is estimated to check convergence. Ground state energies of nuclei up to mass
number A=48 are calculated with a spin-isospin-dependent potential and single
Slater determinants as uncorrelated states. They show that the deduced energy-
and mass-number-independent correlated two-body Hamiltonian reproduces all
"exact" many-body calculations surprisingly well.Comment: 43 pages, several postscript figures, uses 'epsfig.cls'. Submitted to
Nucl. Phys. A. More information available at http://www.gsi.de/~fm
Nonuniversal Effects in the Homogeneous Bose Gas
Effective field theory predicts that the leading nonuniversal effects in the
homogeneous Bose gas arise from the effective range for S-wave scattering and
from an effective three-body contact interaction. We calculate the leading
nonuniversal contributions to the energy density and condensate fraction and
compare the predictions with results from diffusion Monte Carlo calculations by
Giorgini, Boronat, and Casulleras. We give a crude determination of the
strength of the three-body contact interaction for various model potentials.
Accurate determinations could be obtained from diffusion Monte Carlo
calculations of the energy density with higher statistics.Comment: 24 pages, RevTex, 5 ps figures, included with epsf.te
Ground State Energy of the Low Density Bose Gas
Now that the properties of low temperature Bose gases at low density, ,
can be examined experimentally it is appropriate to revisit some of the
formulas deduced by many authors 4-5 decades ago. One of these is that the
leading term in the energy/particle is , where is
the scattering length. Owing to the delicate and peculiar nature of bosonic
correlations, four decades of research have failed to establish this plausible
formula rigorously. The only known lower bound for the energy was found by
Dyson in 1957, but it was 14 times too small. The correct bound is proved here.Comment: 4 pages, Revtex, reference 12 change
Nuclear shell-model calculations for 6Li and 14N with different NN potentials
Two ``phase-shift equivalent'' local NN potentials with different
parametrizations, Reid93 and NijmII, which were found to give nearly identical
results for the triton by Friar et al, are shown to yield remarkably similar
results for 6Li and 14N in a (0+2)hw no-core space shell-model calculation. The
results are compared with those for the widely used Hamada-Johnson hard-core
and the original Reid soft-core potentials, which have larger deuteron D-state
percentages. The strong correlation between the tensor strength and the nuclear
binding energy is confirmed. However, many nuclear-structure properties seem to
be rather insensitive to the details of the NN potential and, therefore, cannot
be used to test various NN potentials. (Submitted to Phys. Rev. C on Nov. 9,
1993 as a Brief Report.)Comment: 12 text pages and 1 figure (Figure available upon request),
University of Arizona Physics Preprint (Number not yet assigned
Magnetic susceptibility of quark matter within Fermi-liquid theory
Possibility of spontaneous magnetization in QCD and magnetic properties of
quark matter is discussed by evaluating the magnetic susceptibility within
Fermi-liquid theory. The screening effects for gluons are taken into account to
figure out the specific properties of the magnetic transition in gauge
theories. It is shown that the static screening effect in terms of the Debye
mass does not necessarily work against the magnetic instability; it promotes
the instability, depending on the coupling constant and the number of flavors.Comment: 10 pages, 2 figure
Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions
Using the SU6 quark-model baryon-baryon interaction recently developed by the
Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in
ordinary nuclear matter. This is the first attempt to discuss the Lambda and
Sigma single-particle potentials in nuclear medium, based on the realistic
quark-model potential. The Lambda potential has the depth of more than 40 MeV,
which is more attractive than the value expected from the experimental data of
Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin
of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2)
^3S_1 state.Comment: 20 pages, 5 figure
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