4,252 research outputs found
Effective Non-Hermitian Hamiltonians for Studying Resonance Statistics in Open Disordered Systems
We briefly discuss construction of energy-dependent effective non-hermitian
hamiltonians for studying resonances in open disordered systemsComment: Latex, 20 pages, 1 fig. Expanded version of a talk at the Workshop on
Pseudo-Hermitian Hamiltonians in Quantum Physics IX, June 21-24 2010,
Zhejiang University, Hangzhou, China. Accepted for publication in the
Internationa Journal of Theoretical Physics (Springer Verlag
Application of ERTS-1 data to the protection and management of New Jersey's coastal environment
The author has identified the following significant results. A Coastal Zone Surveillance Program has been developed in which systematic comparisons of early ERTS-1 images and recently acquired images are regularly made to identify areas where changes have occurred. A methodology for assessing and documenting benefits has been established. Quantification of benefits has been directed toward four candidate areas: shore protection, ocean outfalls, coastal land resources, and offshore waste disposal. A refinement in the change detection analysis procedure has led to greater accuracy in spotting developmental changes in the Coastal Zone. Preliminary conclusions drawn from the Shore Erosion case study indicate that in the northern test area (developed beach) erosion has occurred more often, is generally more severe, and the beach is slower to recover than in the southern test area (natural beach). From these data it appears that it may be possible to define areas most likely to experience further erosion. The assumption of continued erosion in areas that have at one time experienced severe erosion is supported by the simple fact that as a beach narrows wave energy is concentrated on a narrower beach surface. The higher energy condition subsequently results in accelerated erosion
Application of ERTS-1 data to the protection and management of New Jersey's coastal environment
The author has identified the following significant results. Rapid access to ERTS data was provided by NASA GSFC for the February 26, 1974 overpass of the New Jersey test site. Forty-seven hours following the overpass computer-compatible tapes were ready for processing at EarthSat. The finished product was ready just 60 hours following the overpass and delivered to the New Jersey Department of Environmental Protection. This operational demonstration has been successful in convincing NJDEP as to the worth of ERTS as an operational monitoring and enforcement tool of significant value to the State. An erosion/ accretion severity index has been developed for the New Jersey shore case study area. Computerized analysis techniques have been used for monitoring offshore waste disposal dumping locations, drift vectors, and dispersion rates in the New York Bight area. A computer shade print of the area was used to identify intensity levels of acid waste. A Litton intensity slice print was made to provide graphic presentation of dispersion characteristics and the dump extent. Continued monitoring will lead to the recommendation and justification of permanent dumping sites which pose no threat to water quality in nearshore environments
Strange hyperon and antihyperon production from quark and string-rope matter
Hyperon and antihyperon production is investigated using two microscopical
models: {\bf (1)} the fast hadronization of quark matter as given by the ALCOR
model; {\bf (2)} string formation and fragmentation as in the HIJING/B model.
We calculate the particle numbers and momentum distributions for Pb+Pb
collisions at CERN SPS energies in order to compare the two models with each
other and with the available experimental data. We show that these two
theoretical approaches give similar yields for the hyperons, but strongly
differ for antihyperons.Comment: 11 pages, Latex, 3 EPS figures, contribution to the Proceedings of
the 4th International Conference on Strangeness in Quark Matter (SQM'98),
Padova, Italy, 20-24 July 199
Dynamical Generation of Extended Objects in a Dimensional Chiral Field Theory: Non-Perturbative Dirac Operator Resolvent Analysis
We analyze the dimensional Nambu-Jona-Lasinio model non-perturbatively.
In addition to its simple ground state saddle points, the effective action of
this model has a rich collection of non-trivial saddle points in which the
composite fields \sigx=\lag\bar\psi\psi\rag and \pix=\lag\bar\psi
i\gam_5\psi\rag form static space dependent configurations because of
non-trivial dynamics. These configurations may be viewed as one dimensional
chiral bags that trap the original fermions (``quarks") into stable extended
entities (``hadrons"). We provide explicit expressions for the profiles of
these objects and calculate their masses. Our analysis of these saddle points
is based on an explicit representation we find for the diagonal resolvent of
the Dirac operator in a \{\sigx, \pix\} background which produces a
prescribed number of bound states. We analyse in detail the cases of a single
as well as two bound states. We find that bags that trap fermions are the
most stable ones, because they release all the fermion rest mass as binding
energy and become massless. Our explicit construction of the diagonal resolvent
is based on elementary Sturm-Liouville theory and simple dimensional analysis
and does not depend on the large approximation. These facts make it, in our
view, simpler and more direct than the calculations previously done by Shei,
using the inverse scattering method following Dashen, Hasslacher, and Neveu.
Our method of finding such non-trivial static configurations may be applied to
other dimensional field theories
Long range neutrino forces in the cosmic relic neutrino background
Neutrinos mediate long range forces among macroscopic bodies in vacuum. When
the bodies are placed in the neutrino cosmic background, these forces are
modified. Indeed, at distances long compared to the scale , the relic
neutrinos completely screen off the 2-neutrino exchange force, whereas for
small distances the interaction remains unaffected.Comment: 8 pages, 2 figure
Renormalizing Rectangles and Other Topics in Random Matrix Theory
We consider random Hermitian matrices made of complex or real
rectangular blocks, where the blocks are drawn from various ensembles. These
matrices have pairs of opposite real nonvanishing eigenvalues, as well as
zero eigenvalues (for .) These zero eigenvalues are ``kinematical"
in the sense that they are independent of randomness. We study the eigenvalue
distribution of these matrices to leading order in the large limit, in
which the ``rectangularity" is held fixed. We apply a variety of
methods in our study. We study Gaussian ensembles by a simple diagrammatic
method, by the Dyson gas approach, and by a generalization of the Kazakov
method. These methods make use of the invariance of such ensembles under the
action of symmetry groups. The more complicated Wigner ensemble, which does not
enjoy such symmetry properties, is studied by large renormalization
techniques. In addition to the kinematical -function spike in the
eigenvalue density which corresponds to zero eigenvalues, we find for both
types of ensembles that if is held fixed as , the
non-zero eigenvalues give rise to two separated lobes that are located
symmetrically with respect to the origin. This separation arises because the
non-zero eigenvalues are repelled macroscopically from the origin. Finally, we
study the oscillatory behavior of the eigenvalue distribution near the
endpoints of the lobes, a behavior governed by Airy functions. As the lobes come closer, and the Airy oscillatory behavior near the endpoints
that are close to zero breaks down. We interpret this breakdown as a signal
that drives a cross over to the oscillation governed by Bessel
functions near the origin for matrices made of square blocks.Comment: LateX, 34 pages, 3 ps figure
On CP-Odd Effects in K_L \to 2\pi and K^{\pm} \to \pi^{\pm} \pi^{\pm} \pi^{\mp} Decays Generated by Direct CP Violation
The amplitudes of the K^{\pm} \to 3\pi and K \to 2\pi decays are expressed in
terms of different combinations of one and the same set of CP-conserving and
CP-odd parameters. Extracting the magnitudes of these parameters from the data
on K \to 2\pi decays, we estimate an expected CP-odd difference between the
values of the slope parameters g^+ and g^- of the energy distributions of "odd"
pions in K^+ \to \pi^+\pi^+\pi^- and K^- \to \pi^-\pi^-\pi^+ decays.Comment: 12 pages, no figure
Universal eigenvector statistics in a quantum scattering ensemble
We calculate eigenvector statistics in an ensemble of non-Hermitian matrices
describing open quantum systems [F. Haake et al., Z. Phys. B 88, 359 (1992)] in
the limit of large matrix size. We show that ensemble-averaged eigenvector
correlations corresponding to eigenvalues in the center of the support of the
density of states in the complex plane are described by an expression recently
derived for Ginibre's ensemble of random non-Hermitian matrices.Comment: 4 pages, 5 figure
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