8,582 research outputs found
Disturbances of body-experience in acute anxiety and depressive disorders neuroticism or somatization?
Investigations of solutions of Einstein's field equations close to lambda-Taub-NUT
We present investigations of a class of solutions of Einstein's field
equations close to the family of lambda-Taub-NUT spacetimes. The studies are
done using a numerical code introduced by the author elsewhere. One of the main
technical complication is due to the S3-topology of the Cauchy surfaces.
Complementing these numerical results with heuristic arguments, we are able to
yield some first insights into the strong cosmic censorship issue and the
conjectures by Belinskii, Khalatnikov, and Lifschitz in this class of
spacetimes. In particular, the current investigations suggest that strong
cosmic censorship holds in this class. We further identify open issues in our
current approach and point to future research projects.Comment: 24 pages, 12 figures, uses psfrag and hyperref; replaced with
published version, only minor corrections of typos and reference
Simple Max-Min Ant Systems and the Optimization of Linear Pseudo-Boolean Functions
With this paper, we contribute to the understanding of ant colony
optimization (ACO) algorithms by formally analyzing their runtime behavior. We
study simple MAX-MIN ant systems on the class of linear pseudo-Boolean
functions defined on binary strings of length 'n'. Our investigations point out
how the progress according to function values is stored in pheromone. We
provide a general upper bound of O((n^3 \log n)/ \rho) for two ACO variants on
all linear functions, where (\rho) determines the pheromone update strength.
Furthermore, we show improved bounds for two well-known linear pseudo-Boolean
functions called OneMax and BinVal and give additional insights using an
experimental study.Comment: 19 pages, 2 figure
Effective T-odd P-even hadronic interactions from quark models
Tests of time reversal symmetry at low and medium energies may be analyzed in
the framework of effective hadronic interactions. Here, we consider the quark
structure of hadrons to make a connection to the more fundamental degrees of
freedom. It turns out that for P-even T-odd interactions hadronic matrix
elements evaluated in terms of quark models give rise to factors of 2 to 5.
Also, it is possible to relate the strength of the anomalous part of the
effective rho-type T-odd P-even tensor coupling to quark structure effects.Comment: 6 pages, 1 figure, RevTe
Quasilinear hyperbolic Fuchsian systems and AVTD behavior in T2-symmetric vacuum spacetimes
We set up the singular initial value problem for quasilinear hyperbolic
Fuchsian systems of first order and establish an existence and uniqueness
theory for this problem with smooth data and smooth coefficients (and with even
lower regularity). We apply this theory in order to show the existence of
smooth (generally not analytic) T2-symmetric solutions to the vacuum Einstein
equations, which exhibit AVTD (asymptotically velocity term dominated) behavior
in the neighborhood of their singularities and are polarized or half-polarized.Comment: 78 page
Smooth Gowdy symmetric generalized Taub-NUT solutions
We study a class of S3 Gowdy vacuum models with a regular past Cauchy horizon
which we call smooth Gowdy symmetric generalized Taub-NUT solutions. In
particular, we prove existence of such solutions by formulating a singular
initial value problem with asymptotic data on the past Cauchy horizon. The
result of our investigations is that a future Cauchy horizon exists for generic
asymptotic data. Moreover, we derive an explicit expression for the metric on
the future Cauchy horizon in terms of the asymptotic data on the past horizon.
This complements earlier results about S2xS1 Gowdy models.Comment: 56 pages, 1 figure. The new version contains a detailed explanation
of the Fuchsian method on the 2-spher
An Integral Spectral Representation of the Propagator for the Wave Equation in the Kerr Geometry
We consider the scalar wave equation in the Kerr geometry for Cauchy data
which is smooth and compactly supported outside the event horizon. We derive an
integral representation which expresses the solution as a superposition of
solutions of the radial and angular ODEs which arise in the separation of
variables. In particular, we prove completeness of the solutions of the
separated ODEs.
This integral representation is a suitable starting point for a detailed
analysis of the long-time dynamics of scalar waves in the Kerr geometry.Comment: 41 pages, 4 figures, minor correction
Doppler-tuned Bragg Spectroscopy of Excited Levels in He-Like Uranium: a discussion of the uncertainty contributions
We present the uncertainty discussion of a recent experiment performed at the
GSI storage ring ESR for the accurate energy measurement of the He-like uranium
1s2p3P2- 1s2s3S1 intra-shell transition. For this propose we used a Johann-type
Bragg spectrometer that enables to obtain a relative energy measurement between
the He-like uranium transition, about 4.51 keV, and a calibration x-ray source.
As reference, we used the Ka fluorescence lines of zinc and the Li-like uranium
1s22p2P3/2 - 1 s22s 2S1/2 intra-shell transition from fast ions stored in the
ESR. A comparison of the two different references, i.e., stationary and moving
x-ray source, and a discussion of the experimental uncertainties is presented
Doppler-tuned Bragg Spectroscopy of Excited Levels in He-Like Uranium: a discussion of the uncertainty contributions
We present the uncertainty discussion of a recent experiment performed at the
GSI storage ring ESR for the accurate energy measurement of the He-like uranium
1s2p3P2- 1s2s3S1 intra-shell transition. For this propose we used a Johann-type
Bragg spectrometer that enables to obtain a relative energy measurement between
the He-like uranium transition, about 4.51 keV, and a calibration x-ray source.
As reference, we used the Ka fluorescence lines of zinc and the Li-like uranium
1s22p2P3/2 - 1 s22s 2S1/2 intra-shell transition from fast ions stored in the
ESR. A comparison of the two different references, i.e., stationary and moving
x-ray source, and a discussion of the experimental uncertainties is presented
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