bluuebunny/crossref_metadata_2025 huggingface dataset:
Diffraction Theory by Means of Singular Integral Equations. VIIUniform High‐Frequency Asymptotics for the Diffraction of Plane Waves by a Slit
Authors: Lüneburg E. , Westpfahl K.
Published: May 2007

We consider the diffraction of plane waves by a slit between two semi‐infinite halfplanes for arbitrary angles of incidence and DIRICHLET boundary condition (electric field strength parallel to the edges). By a function‐theoretic technique, which treats the angles of observation and incidence on an equal footing, we derive a high‐frequency asymptotic expansion for the far field amplitude, uniformly valid over the whole range of both angles. Our expansion in terms of products of generalized FRESNEL integrals is compared with the known limiting cases of normal and grazing incidence both analytically and numerically including a comparison with MATHIEU‐series results.
NOETHER'S Theorem and Higher Conservation Laws in Ultrashort Pulse Propagation
Authors: Steudel H.
Published: May 2007

LAMB has constructed a number of local conservation laws for the differential equation στ = sin σ describing ultrashort pulse propagation in a resonant medium. On the other hand it is known that from any solution of this equation others may be found by BÄCKLUND transformation.

In this paper we introduce extended BÄCKLUND transformations Ba and compose them to form infinitesimal invariance transformations Ba+ε B from which via NOETHER'S theorem a system of conservation laws follows. Some of them are recognized as LAMB'S conservation laws.

Another conservation law results from a scale invariance called LIE'S transformation.
Kinetische Herleitung verallgemeinerter NERNST‐PLANCK‐Gleichungen. III. Eindimensionales Membranmodell
Authors: Schröter J. , West G.
Published: May 2007

In this part onedimensional models of membranesystems are treated, i.e. such membranes, which are unbounded in two dimensions y, z. The equations of motion for such systems can be derived using the results of part I or of part II. The equation of motion containing the one particle densities can be written in the form of an Onsager relation, the coefficients Lαβ of which are symmetric. The dependence of Lαβ on the densities is calculated. The approximation used up to now in the literature is seen to be the lowest order one. Global balancy equations yield the boundary conditions on surfaces of discontinuities. It is shown that the usually used formula for the Donnan equilibrium is only formally correct.
Quasiparticle Lifetimes in FERMI Systems
Authors: Fennel W. , Wilfer H. P.
Published: May 2007

The one‐particle spectrum in a homogeneous electron gas at metallic densities (rs = 2) and a wide temperature range is calculated explicitly. Thermodynamic properties of the one‐particle spectrum, such as the temperature dependence of the quasiparticle energy and lifetimes, are investigated.
Nichtlineare Wellenleiter der Physik und ihr Vergleich mit Nervenleitungen
Authors: Wolter Hans
Published: May 2007

Die hohe Sicherheit der Signalübermittlung in Nerven des Menschen und der höheren Tiere trotz mangelhafter Isolierung und trotz energiereicher Störungen beruht auf der Nichtlinearität der Synapsen und der Schnürringe. Physikalische Modelle werden mitgeteilt, die zum Verständnis der Wirksamkeit von Nichtlinearitäten beitragen und zugleich quantitative Aussagen über die Sicherheit von Nervenleitungen bringen, sobald eine Größe, das “Gauß‐Äquivalent” γ der Nervenleitung, gemessen sein wird. Solange γ unbekannt ist, wird die Annahme γ ≈ 1 zu ausreichenden Abschätzungen führen.
The Post‐NEWTONian Effect of Gravitation and the Retardation of the Gravitational Potential in Classical and Relativistic Theories of Gravitation
Authors: Treder H.‐J.
Published: May 2007

For planetary motions the post‐NEWTONian approximations of classical, special‐relativistic, and general‐covariant theories are compared. It is shown that, in this approximation, the anisotropy terms, which occur in the effective interaction potential in classical and special‐relativistic theories, suggest a retardation of gravitation. In the post‐NEWTONian approximation of general‐covariant theories the fixation of a retardation velocity is equivalent to coordinate conditions. – All post‐NEWTONian corrections are dipole‐like ones, while, according to GAUSS, the classical perturbation theory generally leads to quadrupole‐like corrections of the perturbation potential.
Unified Field Theory with EINSTEINian Photons and Heavy Bosons as Field Quants
Authors: Treder H.‐J.
Published: May 2007

After discussing in two previous papers [1, 2] the classical electrodynamics which corresponds to the quantum electrodynamics with two sorts of photons (photons with zero rest mass and nonvanishing rest mass), in the present paper the general field theory of a vector field Av with two sorts if field quanta is given. It is shown that the postulate of the “unity of the four‐current” determining the physical contents of this theory makes it possible to regard it as a classical ansatz of a unified theory of the electromagnetic and the weak interactions.

From the “unity of the currents” results that the electrons are δ‐like point‐particles with a finite self‐potential and finite field masses M = ε2/2 kc−2. The COMPTON wave‐length of the heavy photons k−1 = h/mc has the meaning of an “elementary length” for the electromagnetic interactions and the rest mass m = khc−1 of these bosons is of the order of a baryon mass.
2nd Class Currents in Neutrino Reactions
Authors: Rodenberg R.
Published: May 2007

The influence of 2nd class currents in neutrino reactions is investigated. We show that WEINBERG'S unified model of electromagnetic and weak interactions implies both neutral and 2nd class currents. Possible experimental effects due to 2nd class neutral weak currents are discussed. Further, we investigate implications of 2nd class charged currents for hadronic neutral weak currents. It is shown that if 2nd class charged currents exist, the isospin I = 1 axial‐vector neutral current must be a “new” current, or it must contain a “new” I = 1 part. 2nd class charged currents are excluded if the I = 1 axial‐vector neutral current is “old”, i.e., if it is proportional to the third component of the charged current. Then also the proportionality constant is real. CP invariance is assumed throughout the discussion.
Bound State Effects in Quantum Transport Theory
Authors: Ebeling W.
Published: May 2007

A quantum kinetical equation for the one‐particle density operator for inhomogeneous multi component non‐ideal gases is derived taking into account retardation effects and external fields. It is shown that the interactions give rise to additional contributions to the quantities in the transport equation. In some terms (e.g., internal energy, pressure, effective external force) the interaction effects are strong in the presence of bound states and yield contributions of the order exp (—E10/kT) where E10 is the ground state energy of bound pairs of particles. Other terms (e.g. friction forces) are rather insensitive with respect to the presence of bound states. An interpretation of these effects in terms of the mass action law is given using the principle of equivalence between bound states and particles.
Analytic Treatment of Proton Induced Electromagnetic Cascades
Authors: Barmo S.
Published: May 2007

The electromagnetic cascade induced by the π0's produced by the interaction of a proton and its secondaries (mainly π±'s) is described.

Simple considerations indicate that a large part of the energy of the proton is used to produce π0's (see Appendix B). Using the scaling hypothesis of FEYNMAN we derive analytical solutions for the cascade equations.

The solution indicate that at the beginning of the cascade the π0's produced by the nucleon are more important for the development of the cascade than those produced by π±'s. The situation changes with increasing atmospheric depth. The average energy of the electrons and photons is nearly the same as indicated by the above mentioned simple considerations. A comparison with a photon induced cascade shows that the proton induced electromagnetic cascade is developing slowly and living longer.
Numerical Inversion of the Abel Integral Function, Using Least‐Squares Splines
Authors: Bock T. L.
Published: May 2007

In the Abel inversion of a function whose values are determined experimentally on a discrete set of points, random errors are amplified considerably. This paper presents a procedure to smooth the data before inversion, and thus keep the error amplification under control.
Sättigungsspektroskopie mit verzögerten Impulsen
Authors: Mohr U.
Published: May 2007

Die Breite und die Tiefe des im Absorptionsprofil eines schwachen Probeimpulses entstehenden Lambdips werden für den Fall theoretisch untersucht, daß der sich in entgegengesetzter Richtung ausbreitende starke Sättigungsimpuls das absorbierende gasförmige Medium beim Eintreffen des Probeimpulses schon vollständig durchlaufen hat. Letzterer wird als rechteckförmig oder exponentiell abklingend angenommen, und weiterhin werden geschwindigkeitsändernde Stöße vernachlässigt. Es zeigt sich, daß der Lambdip bei starker Doppler‐Verbreiterung und im Grenzfall großer Sättigung die Gestalt einer Lorentzkurve hat, deren Tiefe mit zunehmender Zeitverzögerung zwischen den Impulsen und mit wachsender Probeimpulslänge abnimmt, während ihre durch die Intensitätsverbreiterung bestimmte Halbwertsbreite konstant bleibt.

Zur Durchführung der Untersuchungen dient der Dichtematrixformalismus, in dem kohärente Effekte Berücksichtigung finden, und die Resultate werden mit denjenigen verglichen, die sich bei bloßer Betrachtung der Sättigung der Niveaubesetzung ergeben.
Zur Theorie der strahlungslosen Energierelaxation vieler miteinander wechselwirkender Molekülnormalschwingungen
Authors: Paerschke H. , Süsse K.‐E. , Welsch D.‐G.
Published: May 2007

Auf der Grundlage einer von den Autoren entwickelten Relaxationstheorie wird im Rahmen einer Bilanzgleichungstheorie die Energiedissipation und ‐übertragung in einem aus einer Vielzahl miteinander wechselwirkender Molekülnormalschwingungen bestehenden System unter Umgehung der üblichen Wärmebadnäherung untersucht. Eine Spezialisierung wird für den Fall vorgenommen, daß es sich jeweils um gleiche Schwingungen räumlich dicht angeordneter Moleküle handelt. Für unterschiedliche Wechselwirkungspotentiale werden verallgemeinerte, zeitabhängige Dämpfungsgrößen berechnet und mit ihrer Hilfe das zu erwartende nichtexponentielle Relaxationsverhalten abgeschätzt.
Einfluß von Drehungen auf die piezoelektrische und photoelastische Wechselwirkung im kristallinen Medium
Authors: Macheleidt G.
Published: May 2007

Wegen der Drehmomente, die durch die elektrische Polarisation im Festkörper erzeugt werden, ist der Spannungstensor nicht mehr symmetrisch, so daß auch der antisymmetrische Anteil des Distorsionstensors thermodynamische Zustandsvariable wird. Die entsprechenden antisymmetrischen Anteile der piezoelektrischen und photoelastischen Materialtensoren werden durch die spontane elektrische Polarisation bzw. die lineare elektrische Suszeptibilität ausgedrückt. Einige Konsequenzen werden ‐ auch hinsichtlich numerischer Werte ‐ diskutiert.
Dao Scaling Model and Sea Level Cosmic Ray Muon Spectrum from Goddard Space Flight Group Measured Primary Proton Spectrum
Authors: Bhattacharyya D. P. , Roychoudhury R. K. , Basu D.
Published: May 2007

A new type of scaling model for p + p → π− + X inclusive reactions, proposed by DAO et al., is applied to derive the sea level muon spectrum. The nucleon spectrum data of Goddard Space Flight Group were taken as input. It is found that the sea level muon spectrum depends explicitly on the average value of the FEYNMAN variable x whose most probable value is estimated to be 0.18.
Orientierung nematischer Phasen im Magnetfeld
Authors: Braun P. , Grande S. , Limmer S. , Hillner B.
Published: May 2007

Es werden zwei Methoden zur Bestimmung der Rückorientierungszeiten τ0r des Direktors in der nematischen Phase von flüssig‐kristallinen Substanzen im äußeren Magnetfeld beschrieben. Beide Verfahren liefern die gleichen Aussagen; ihre Vor‐ und Nachteile werden gegenübergestellt. Die ersten Resultate zeigen, daß die aus der Kontinuumstheorie resultierende Bedingung tan Φ ∞e−t/τ0r erfüllt wird (Φ Drehwinkel). Im Anhang diskutieren wir Optimierungsbedingungen für die Impulsmethode.
Vakuum‐Lichtgeschwindigkeit und differentielle Aberration
Authors: Treder H.‐J.
Published: May 2007

Laplace hat 1796 im Rahmen der Newtonschen Gravitationstheorie und der Newtonschen Emanationstheorie des Lichtes die Hypothese abgeleitet, daß die effektive Lichtgeschwindigkeit c* des Lichtes eine Funktion des Gravitationspotentials am Ort r = R seiner Emission ist:

equation image

Laplace, Olbers u. a. schlossen hieraus auf eine differentielle Aberration des Lichtes verschiedener kosmischer Quellen. – Einsteins Relativitätsprinzipien lehren dagegen die Unabhängigkeit der Lichtgeschwindigkeit von den Quellen. Dieses Lichtprinzip ist fundamental für die Einsteinschen Relativitätstheorien. Merkwürdigerweise scheint aber Laplaces Hypothese noch nicht direkt und streng experimentell widerlegt worden zu sein.
Theory of Gravitational‐Inertial Field of Universe
Authors: Davtyan O. K.
Published: May 2007

In this paper the basic proposition is a generalization of the metric tensor by introduction of an inertial field tensor satisfying ∇iglm  glm;i ≠ 0. On the basis of variational equations a system of more general covariant equations of gravitational‐inertial field is obtained. In Einstein's approximation these equations reduce to the field equations of Einstein. The solution of fundamental problems of generl taheory of relativity by means of the new equations give the same results as Einstein's equations. However application of these equations to the cosmologic problem leads to following results: 1. All Galaxies in the Universe (actually all bodies if gravitational attraction is not considered) “disperse” from each other according to Hubble's law. Thus contrary to Friedmann's theory (according to which the “expansion of Universe” began from the singular state with an infinite velocity) the velocity of “dispersion” of bodies begins from the zero value and in the limit tends to the velocity of light. 2. The “dispertion” of bodies represents a free motion in the inertial field and Hubble's law represents a law of motion of free bodies in the inertial field ‐ the law of inertia.

All critical systems (with Schwarzschild radius) are specific because they exist in maximal inertial and gravitational potentials. The Universe represents a critical system, it exists under the Schwarzschild radius. In the high‐potential inertial and gravitational fields the material mass in a static state or in the process of motion with decelleration is subject to an inertial and gravitational “annihilation”. Under the maximal value of inertial and gravitational potentials (= c2) the material mass is completely “evaporated” transforming into a radiation mass. The latter is concentrated in the “horizon” of the critical system.

All critical systems –“black holes”‐ represent geon systems, i.e., the local formations of gravitational‐electromagnetic radiations, held together by their own gravitational and inertial fields. The Universe, being a critical system, is “wrapped” in a geon crown.

The Universe is in a state of dynamical equilibrium. Near the external part of its boundary surface a transformation of matter into electromagnetic‐gravitational‐neutrineal energy (geon mass) takes place. Inside the Universe, in the galaxies takes place the synthesis of matter from geon mass, penetrating from the external part of the world (from geon crown) by means of a tunneling mechanism.

The geon system may be considered as a natural entire cybernetic system.
Radiation Properties of a Continuously Pumped Two‐Atom System
Authors: Steudel H. , Richter Th.
Published: May 2007

Radiation rate, angular distribution, spectrum, and intensity correlations of the radiation of a continuously pumped two‐atom system are calculated using Lehmberg's master equation and the fluctuation‐regression theorem. As one remarkable result we found that under certain conditions an increasing radiation rate can be accompanied by a spectral narrowing, see Fig. 4.
Teilchen‐Modelle und effektive Radien in der Allgemeinen Relativitätstheorie
Authors: Treder H.‐J.
Published: May 2007

Für die allgemeine Relativitätstheorie formulierte EINSTEIN das „Teilchen‐Problem”︁ als Gravitations‐Analogon der Teilchen‐Modelle in den klassischen speziell‐relativistischen Feldtheorien. Wir zeigen, daß auch in den Teilchen‐Modellen gemäß der Allgemeinen Relativitätstheorie ein effektiver Teilchen‐Radius resultiert; dieser ist hier durch den Schwarzschild‐Radius zur mechanischen Masse m eines Teilchens gegeben. Aber diese Teilchen mit endlichem Teilchen‐Radius sind nicht selbstkonsistent.
Inclusive Single Particle Distributions from the Dual Fermion Model
Authors: Becker L. , Biebl K.‐J. , Weigt G.
Published: May 2007

Inclusive single particle distributions are calculated from the discontinuity of a phenomenological 4π NN amplitude obtained from the Neveu‐Schwarz‐Ramond dual fermion model. In contrast to former calculations using the conventional Veneziano B6‐function we get a correct triple Regge behaviour at x ≈ 1 with correct pole position in the t‐channel which is able to reproduce the data. The pomeron, not contained in the dual Born amplitude, is taken into account phenomenologically in the NN channel. Other pomeron contributions are subtracted from the data. We compare the inclusive pion distributions of the model in the beam fragmentation and central region with experimental data for reactions π + N → + X at 8 and 16 GeV/c.
On the Interaction of Fermion and Boson Fields with the Gravitational Field
Authors: Kasper U.
Published: May 2007

We point out that the gravitational field taken by itself cannot be considered as a gauge field. Only an affinity and not a metric can serve as a gauge field. Originally, metric and affinity are completely independent of each other. This fact allows in a natural way to formulate a restricted principle of relativity, according to which only fermion fields may show that there exist a priori distinguished frames of reference. Furthermore, we can couple the gravitational field to boson and fermion fields such that the flat metric or tetrads orthonormalized with respect to this flat metric appearing in the special relativistic matter Lagrangian, are replaced by a Riemannian metric and tetrads orthonormalized with respect to this metric (principle of most minimal gravitational coupling). This coupling principle is a strong restriction on the existence of independent boson fields. Only scalar and vector fields and their different pseudoquantities are possible as independent fields. Boson fields of higher rank are to be considered as fusions of these (pseudo)scalar and (pseudo)vector fields. Theire field equations follow from those of the (pseudo)scalar and (pseudo)vector fields.
Theory of Gravitational‐Inertial Field of Universe. I. Gravitational‐Inertial Field Equations
Authors: Davtyan O. K.
Published: May 2007

In the series of present articles the original proposition is a generalization of the real world tensor by the introduction of a inertial field tensor. From this generalization it follows, particularly, that ∇iglm  glm;i ≠ 0. This allows to use as a Lagrangian density of the field the expression Ag = k1 glm;iglm ;kgik. On the basis of variational equations a system of more general covariant equations of the gravitational‐inertial field is obtained. In the Einstein approximation these equations reduce to the field equations of Einstein. The solution of fundamental problems in the general theory of relativity by means of the new equations gives the same results as the solution by means of Einstein's equations. However, application of these equations to the cosmologic problem gives a result different from that obtained by Friedmann's theory. In particular, the solution gives the Hubble law as the law of motion of a free body in the inertial field ‐ in contrast to Galileo‐Newton's law.
Theory of Gravitational‐Inertial Field of Universe. II. On Critical Systems in Universe
Authors: Davtyan O. K.
Published: May 2007

Application of the equations of the gravitational‐inertial field to the problem of free motion in the inertial field (to the cosmologic problem) leads to results according to which 1. all Galaxies in the Universe “disperse” from each other according to Hubble's law, 2. the “dispersion” of bodies represents a free motion in the inertial field and Hubble's law represents a law of motion of free body in the inertial field, 3. for arbitrary mean distribution densities of space masses different from zero the space is Lobachevskian.

All critical systems (with Schwarzschild radius) are specific because they exist in maximalinertial and gravitational potentials. The Universe represents a critical system, it exists under the Schwarzschild radius.

In high‐potential inertial and gravitational fields the material mass in a static state or in motion with deceleration is subject to an inertial and gravitational “annihilation”. At the maximal value of inertial and gravitational potentials (= c2) the material mass is being completely “evaporated” transforming into radiation mass. The latter is being concentrated in the “horizon” of the critical system.

All critical systems‐black holes‐represent geon systems, i.e. local formations of gravitational‐electromagnetic radiations, held together by their own gravitational and inertial fields. The Universe, being a critical system, is “wrapped” in a geon crown.
Reflexion und Brechung des Lichtes an optisch einachsigen Medien
Authors: Wünsche A.
Published: May 2007

Die Formeln für die Amplitudenverhältnisse bei der Reflexion und Brechung ebener monochromatischer Lichtwellen an einer Grenzebene zwischen einem isotropen und einem beliebig anisotropen Medium, die in einer früheren Arbeit des Autors abgeleitet wurden, werden hier auf den Fall optisch einachsiger Medien spezialisiert. Es wird der Einfall sowohl vom isotropen als auch vom optisch einachsigen Medium her behandelt. Eine Reihe von Spezialfällen (senkrechter Einfall, optische Achse parallel oder senkrecht zur Einfallsebene, Übergang von einachsigen zu isotropen Medien u.a.) wird betrachtet.
Transverse Momentum and Rapidity Distributions of Charged Secondaries Emitted in Proton Nucleon Inelastic Interactions at 69 Gev/c
Authors: Badawy O. E. , Abd‐el‐Salam A.
Published: May 2007

This paper deals mainly with the study of the transverse momentum and the rapidity distributions of the charged secondaries emitted in the proton‐nucleon inelastic scattering at 69.0 Gev/c. Our sample consists of 300 proton‐nucleon inelastic events, found amongst 1887 stars attributed to inelastic interactions of 69 Gev/c protons with emulsion nucleons and nuclei, in 768 meters of proton tracks. Our plates were obtained from the JINR Dubna, USSR. Accurate coulomb scattering mesuremments were performed on about 300 emitted charged secondaries to determine their momenta.

The average value of the transverse momentum 〈Pt〉 of the charged secondaries emitted in p‐nucleon, p‐p, and p‐n interactions at 69 Gev/c are 0.329 ± .020, 0.317 ± .029 and 0.332 ± .027 Gev/c respectively. The 〈Pt〉 value is almost constant for primary energies from above 6.0 Gev up to cosmic ray energies. It slightly decreases as the charged multiplicity increases as expected according to the statistical models.

It is found that the linear and the Hagedorn distribution (LD and HD), both fit the experimental transverse momentum distributions better than the Boltzmann distribution (BD) in the energy range from above 6.0 Gev up to cosmic ray range.

In all the cases of p‐nucleon, p‐p and p‐n interactions at our energy, it has been found that the HD gives 〈Pt〉 values nearer to the experimental results than the LD.

The different order moments of the experimentally obtained transverse momentum distribution strongly confirms the applicability of the generalized HD at our energy and in the range of interaction from above 6.0 Gev up to cosmic ray ranges.

The temperature of the interaction volume was determined to be 140 Mev in agreement with the Hagedorn model which predicts it to be of the order of one pion mass.

The variation of 〈Pt〉 with the angle of emission in the C.M. system and the momentum distribution in the C.M. system were studied in view of the isobar model.

A study of the rapidity (Y) distribution confirmed an energy independent behaviour especially for slow emitted pions both in the projectile and the target fragmentation regions in accordance with the limiting fragmentation hypothesis.
Power Asymptotes of Homogeneous Cosmological Models in Einstein's Theory of Gravitation
Authors: v. Borzeszkowski H.‐H. , Müller V.
Published: May 2007

For the Bianchi‐types I, V, VII, VIII, and IX, the asymptotes of the metric, which show a power‐like dependence on the synchronized time t near the cosmological singularity, are investigated. Comparing the influence of the terms which in Einstein's equations describe time‐derivatives, spatial curvature, and matter, on the behaviour of the asymptotes, different assumptions and conjectures usually used in literature are discussed for the equations of state p = βϱ (0 ⩽ β ⩽ 1). For Bianchi‐type‐IX models both the outgoing power‐asymptotes and the oscillatory phase for t → 0 are considered.
Theorie der optimalen Fokussierung für die direkte Erzeugung höherer optischer Harmonischer
Authors: Fischer R. , Wieczorek L.‐W.
Published: May 2007

Es werden die Bedingungen für eine optimale Fokussierung Gaußscher Strahlen bei der direkten Erzeugung höherer Harmonischer abgeleitet. Der Abbau der Grundwelle wird vernachlässigt. Für die Grenzfälle schwacher und starker Fokussierung werden analytische Lösungen angegeben. Darüber hinaus werden die Ergebnisse einer numerischen Optimierung mitgeteilt.

Als wesentlichstes Resultat ergibt sich, daß bei höheren Harmonischen unter optimalen Fokussierungsbedingungen eine starke Fokussierung günstig ist. Die Leistung der mten Harmonischen ist für m > 3 proportional zu ( Fokussierungsparameter, L Länge des nichtlinearen Mediums, b Konfokalparameter der Grundwelle).

Die numerische Optimierung wird bis zur 7. Harmonischen durchgeführt.
Reflexion und Brechung an optisch einachsigen Medien in Richtung fehlender Doppelbrechung
Authors: Wünsche A.
Published: May 2007

Es werden die Amplitudenbeziehungen für die Reflexion und Brechung ebener monochromatischer Wellen an optisch einachsigen Medien bei fehlender Doppelbrechung der gebrochenen bzw. reflektierten Wellen im optisch einachsigen Medium durch Grenzübergang aus früher abgeleiteten verallgemeinerten Fresnelschen Formeln gewonnen. Dabei wird der Einfall sowohl vom isotropen als auch vom optisch einachsigen Medium her betrachtet. Die Grenzbedingungen lassen sich im betrachteten Falle nur durch Hinzunahme von gebrochenen bzw. reflektierten Wellen mit normal zur Grenzebene linear veränderlicher Amplitude im optisch einachsigen Medium erfüllen. Die Forderung fehlender Doppelbrechung schränkt die mögliche Wahl der gemeinsamen Tangentialkomponenten aller Refraktionsvektoren und folglich auch der Refraktionsvektoren der einfallenden Wellen von einer ursprünglich zweidimensionalen komplexen Mannigfaltigkeit auf eindimensionale komplexe Mannigfaltigkeiten ein, die in der Arbeit bestimmt werden.
The Influence of Multi‐Photon Absorption on Photon Statistics
Authors: Mohr Ulrike , Paul Harry
Published: May 2007

A previous approximation scheme [6] which allowed to calculate, in a simple manner, the quantity Δn2/n (n mean value and Δn2 variance of the photon number) in the course of a multi‐photon absorption process, is extended to study the change of the shape of the photon distribution, too. It turns out that there is a tendency to symmetrize the distribution. Moreover, an approximative expression for the asymptotic distribution to which the distribution tends after a sufficiently strong absorption, irrespective of the initial distribution, is found in form of a Gaussian.
Zur Theorie der Resonanzstreuung an Störstellen im Festkörper
Authors: Süsse K.‐E. , Vogel W. , Welsch D.‐G.
Published: May 2007

Es werden zunächst allgemeine Formeln hergeleitet, die es ermöglichen, die Resonanzstreuung sowohl im stationären als auch nichtstationären Bereich bei schwachen Anregungsfeldern zu behandeln. Unter Berücksichtigung der Tatsache, daß die Phasenrelaxation elektronischer Übergänge eines Störstellenatoms im Festkörper nicht durch konstante Relaxationsraten beschreibbar ist, wird der Einfluß von 1‐ und 2‐Phonon‐Prozessen auf das stationäre Resonanz‐Streuspektrum untersucht.
Proximity Effect and Josephson Current in Superconducting Sandwich Systems near Transition Temperature
Authors: Knauer H. , Richter J. , Seidel P.
Published: May 2007

Near the superconducting transition temperature pairpotential behaviour and supercurrent in nonhomogeneous sandwich systems of SNS‐and SINIS‐types (S superconductor, N normal metal, I insulator) are theoretically investigated. The proximity effect is taken into account by using an extrapolation length which relates the order parameter value to its first derivative at interfaces. In frame of the microscopic theory of superconductivity this extrapolation length follows with the help of an appropriate variational principle which has been checked on systems which allow exact solutions. The resulting supercurrent expressions are discussed in detail with respect to temperature dependence and impurity influence.
Electromagnetic Fields of Non‐Equilibrium Plasmas
Authors: Isihara A.
Published: May 2007

A statistical treatment of the electromagnetic fields of a fully ionized plasma shows that there are two types of radiation. One of the radiation fields is determined by the time change of the distribution function and is characteristic of such plasmas. When the time change is due to the many‐body couplings of the charges in the plasma, the radiation can be related to the nonequilibrium stress tensor. In particular, for large distances the radiation is determined by the total internal pressure in a way similar to the classical Larmor formula for a point charge.
Stationäre und nichtstationäre nichtlineare optische Spektroskopie an Oberflächenpolaritonen
Authors: Ponath H. E.
Published: May 2007

Es wird eine phänomenologische Theorie zur Ausbreitung nichtstationärer elektromagnetischer Oberflächenwellen entlang der Grenzfläche zweier homogener isotroper Medien entwickelt. Die verkürzten Wellengleichungen für Oberflächenwellen, die durch äußere Kräfte (nichtlineare Polarisationen und Materiefluktuationen) getrieben werden, werden aufgestellt. Am Beispiel der spontanen und stimulierten Ramanstreuung an Oberflächenpolaritonen wird die Beschreibung nichtlinearer optischer Effekte durch verkürzte Wellengleichungen dargelegt.
NMR‐Linienverschmälerungsexperimente mit großem Resonanzoffset zur Untersuchung von Festkörpern
Authors: Müller Rudolf , Scheler Gerhard
Published: May 2007

Zusammenfassung. Die vorliegende Arbeit beschäftigt sich mit einer Reihe von speziellen leicht zu realisierenden Vielimpulsfolgen, die mit einem großen Resonanzoffset arbeiten und einen für viele Anwendungen ausreichenden Verschmälerungseffekt aufweisen. Nach einleitenden Bemerkungen werden zunächst in einem theoretischen Abschnitt die grundlegenden physikalischen Eigenschaften dieser Verfahren diskutiert. Anschließend werden in einem experimentellen Teil erste Ergebnisse beschrieben.
Die Berücksichtigung der Ionisation durch Elektronenstoß in der Elektronenkinetik des schwachionisierten anisothermen Plasmas. II Anwendung auf das stationäre Plasma
Authors: Wilhelm J. , Winkler R.
Published: May 2007

Ausgehend von der in [1] gegebenen Analyse des Stoßintegrals für die direkte Elektronenstoßionisierung in der Boltzmanngleichung und der für verschiedene Modelle des Ionisierungsprozesses dort hergeleiteten Darstellungen werden diese jetzt zu elektronenkinetischen Untersuchungen unter Berücksichtigung der Direktionisation verwendet. Dabei wird in diesem Teil zunächst der Einfluß ionisierender Stöße und seine Abhängigkeit von den gewählten Modellen an Hand konkreter numerischer Berechnungen am Beispiel des schwachionisierten anisothermen stationären Ne‐Plasmas verfolgt. Die Interpretation der Ergebnisse erlaubt generelle Aussagen über die Größen dieses Einflusses und eine möglichst einfache Beschereibung ionisierender Stöße.
Discussion of Vector Meson Production in Kp Interactions in Terms of a Simple Quark Fusion Model
Authors: Gensch U. , Kriegel U.
Published: May 2007

The inclusive production of ϱ°(773), K*(892) and φ(1020) mesons in K+p and K−p interactions at 32 GeV/c is investigated in terms of a quark fusion model. Except for the ϱ°(773) production, the model fails to give a unique description of the vector meson production in both K+ and K− induced reactions.
On the Exponentiation of Infrared Logarithms in Massless (φ3)6‐theory
Authors: Dörfel B. , Dorn H. , Mann G.
Published: May 2007

We investigate the relation between the coefficients of the perturbative series for the propagator in massless theories and the coefficients of the perturbative series of the renormalization group quantities. This enable us to prove, that the concept of exponentiation in the sense introduced by POGGIO is valid in massless theories to arbitrary high order at the leading log level, but breaks down if nonleading log's are included.
Simultaneous Measurement, Phase‐Space Distributions, and Quantum State Determination
Authors: Park J. L. , Band W. , Yourgrau W.
Published: May 2007

Noting that a classical phase‐space probability distribution w(q, p) may be calculated from moment expectation values {qmpn}, we inquire as to whether similar data in quantum mechanics would be adequate to determine the statistical operator ϱ. For the family of simultaneous (q, p) measurement schemes investigated, it turns out that such moments do not suffice to fix ϱ. Comparison of the empirical information that is adequate to determine ϱ with that required to find w(q, p) reveals that in a sense more data are needed for state determination in quantum statistics than are needed in the classical case.
Zur Greenschen Funktion optisch anisotroper Medien
Authors: Macheleidt G.
Published: May 2007

Die zeitlich fouriertransformierte Greensche Tensorfunktion optisch anisotroper Medien wird in der Fernfeldnäherung berechnet. Dabei wird die räumlich und zeitlich fouriertransformierte Tensorfunktion nach den Eigenvektoren der homogenen Fresnelgleichung entwickelt und die räumliche Rücktransformation in der asymptotischen Näherung mit der Integrationsmethode der stationären Phase ausgeführt. Als Anwendungsbeispiel wird das Strahlungsfeld eines elektrischen Dipols in einem optisch anisotropen Medium behandelt. Alle Ergebnisse werden für den Fall optisch einachsiger Kristalle diskutiert.
The Influence of Intramolecular Coupling between v(XH) and v(XH…Y) Modes on the IR Absorption Spectra of Hydrogen Bonded Species XH…Y
Authors: Mühle S. , Süsse K.‐E. , Welsch D.‐G.
Published: May 2007

By modifying the simple Morse oscillator model usually used for describing the vibrational motion of a linear XH…Y complex a more realistic model is proposed, which is in better agreement with experimental results. The potential energy surface is derived by fitting the bond length, the dissociation energy of the H‐bond, the bond length shortening, and the normal frequency of the v(XH) vibration to their observed values. From the resulting values of the transition matrix elements between low excited v(XH) and high excited v(XH…Y) quantum states it is shown, that for explaining the smoothness of the IR absorption bands the intramolecular coupling between v(XH) and v(XH…Y) stretching modes of vibration should be taken into account.
Bestimmung der Abschirmung der magnetischen Kernresonanz und der magnetischen Suszeptibilität durch Berechnung der Stromdichte diamagnetischer Moleküle mit der Methode der finiten Elemente
Authors: Salzer K.
Published: May 2007

In [20] wurde die Methode der finiten Elemente zur Berechnung diamagnetischer Molekülparameter auf der Basis eines semiklassischen Verfahrens [18, 19] eingeführt. In der vorliegenden Arbeit wird diese Methode im Rahmen der ungekoppelten Hartree‐Fock‐Störungstheorie angewendet. Es wird gezeigt, daß das vorgeschlagene Verfahren auf lokalisierte Orbitale anwendbar ist, was eine Zerlegung von Suszeptibilität und Abschirmung in inkrementäre Beiträge bewirkt. Weiterhin wird der Zusammenhang zu dem semiklassischen Verfahren und zum Verfahren nach Rebane [7] gezeigt. Am Beispiel des H2‐Moleküls, des dreidimensionalen anisotropen harmonischen Oszillators und des CH4‐Moleküls werden die Möglichkeiten dieses Verfahrens dargestellt.
A Modification of Förster's Deactivation Relation due to Inhomogeneous Spatial Distribution and Active Behavior of the Acceptors
Authors: Schubert M. , Vogler K.
Published: May 2007

The deactivation behavior of excited molecules and impurities in solids is analyzed under consideration of a long‐range excitation energy transfer based on dipole‐dipole interaction between donors and acceptors. Under the condition of inhomogeneous spatial distribution and active behavior of the acceptors a time evolution formula is derived, which essentially differs from Förster's original relation [2]. The results are discussed for physically representative values of concentration and medium parameters.
On the Dielectric‐Metal Transition in Hydrogen
Authors: Franck S.
Published: May 2007

A microscopic model for describing the dielectric‐metal transition in hydrogen is derived with the help of methods of statistical mechanics. The Hamiltonian corresponds formally to the so‐called transverse Ising model. Taking from literature numerical values for certain parameters one may calculate the critical temperature Tc above which any jump‐like change at the phase transition vanishes. Tc should be in the range of 6…9 · 103 K which has consequences for the internal structure of the giant planets Jupiter and Saturn.
On the Parameters of the Hellman‐like Model Potential
Authors: Seifert T.
Published: May 2007

There are several sets of parameters of the often used Hellman‐like model potential discussed which had been determined by variational fitting within different basis sets. It is shown that Slater‐type orbitals (STO) form a useful variational basis. There are well approximated parameter values obtainable even if only one STO is used.
On Nonstatistical Effects in Nuclear Reactions
Authors: Rotter Ingrid
Published: May 2007

Different types of nonstatistical effects in nuclear reactions are discussed on the basis of a unified description of nuclear reaction and nuclear structure aspects. Particular attention is devoted to the problem of nuclear molecular states.
β‐decay of Polarized Neutrons in External Electromagnetic Fields
Authors: Ternov I. M. , Rodionov V. N. , Zhulego V. G. , Studenikin A. I.
Published: May 2007

In this paper we consider the β‐decay of a resting polarized neutron in the superposed field of a plane electromagnetic wave and a homogeneous magnetic field. A detailed analysis of the properties of the probability is presented.
A Quark Model for Baryon Production at Low Transverse Momentum
Authors: Becker L.
Published: May 2007

A quark model for baryon production at low pT is obtained as generalization of the quark‐antiquark fusion model. The quark transverse momenta are taken into account using an average transverse mass of the quarks. This leads to the incorporation of both quark fusion and quark recombination into one model. The model is able to describe qualitative features of the reactions pp → (Δ, ¯Δ, ∑+, ∑−) + X at 12 and 24 GeV/c.
The Einsteinian Star Model in Treder's Tetrad Theory of Gravitation
Authors: Gottlöber S.
Published: May 2007

By means of a simple star model proposed by EINSTEIN (point‐particle cluster) the collapse behaviour in General Relativety and in TREDER's [14] Tetrad Theory has been compared. Within both theories the heavy mass of a point‐particle cluster with a fixed radius cannot exceed a critical value. However, contrary to General Relativity, within the framework of TREDER's Tetrad Theory, for a fixed particle number N, the radius of the cluster is allowed to be arbitrarily small. In this sense, the Tetrad Theory is a collapse‐free relativistic theory of gravitation.
Radiation Properties of Systems of Three and Four Continuously Pumped Atoms
Authors: Steudel H.
Published: May 2007

Radiation properties of three and four atoms continuously pumped by an incoherent excitation mechanism are investigated by using Lehmberg's master equation and the quantum fluctuation‐regression theorem.

For proper configurations we found in comparison with independent atoms simultaneously (i) an enlargement of the radiation rate, (ii) a spectral narrowing and (iii) a reduction of intensity fluctuations.
Zur Bestimmung chemischer Verschiebungen der NMR‐Frequenzen bei Quadrupolkernen aus den MAS‐NMR‐Spektren
Authors: Müller D.
Published: May 2007

Die allgemeinen Ausdrücke für den NMR‐Zentralübergang für Quadrupolkerne mit halbzahligem Spin bei Probenrotation, die von BEHRENS [1, 2] unter Berücksichtigung von Quadrupolwechselwirkungseffekten 2. Ordnung für beliebige Neigungswinkel der Rotationsachse abgeleitet wurden, werden für den praktisch interessierenden Fall der Probenrotation um den magischen Winkel (“magic angle spinning”, MAS) in einer den Ausgangsformeln für das “Ruhespektrum” (ohne Probenrotation) analogen Form dargestellt. Am Beispiel der 27Al‐NMR‐Spektren zweier Aluminate wird die Theorie überprüft und zur exakten Ermittlung der chemischen Verschiebungswerte aus den MAS‐Spektren eingesetzt.
Discussion of the Klimontovich Theory of Hydrodynamic Turbulence
Authors: Ebeling W.
Published: May 2007

The Klimontovich Theory which yields the effective turbulent viscosity as a linear function of the Reynolds number is compared with experimental data. The new theory seems to be able to describe the observed effective viscosity of hydrodynamic vortices and after introducing some modifications the flow in tubes up to very high Reynold numbers.
Solitonen in Wellenleitern mit nichtlinearer optischer Beschichtung
Authors: Eichhorn H. , Ponath H.‐E.
Published: May 2007

Ausgehend von den Maxwellgleichungen wird der Einfluß einer dünnen, nichtlinearen optischen Schicht in einem Wellenleiter auf die Ausbreitung eines Mono‐TE‐Modenimpulses untersucht. Die Impulsamplitude gehorcht einer nichtlinearen Schrödingergleichung (NLS), die wellenleiter‐ und schichtspezifische Parameter enthält und Anlaß zu Solitonen im nichtlinear beschichteten Wellenleiter gibt.
Isotrope und homogene Materie – „Kosmen”︁
Authors: Treder H.‐J.
Published: May 2007

Die Dynamik und Thermodynamik großer kosmischer Systeme ist fast unabhängig von den besonderen Theorien über die Gravitation. Nur die Feinstruktur der Kosmologie und Kosmonogie reflektiert die speziellen Hypothesen. Diese Neutralität gegenüber den konkreten Gravodynamiken ist die Konsequenz der fundamentalen Eigenschaften der Gravitation: Der Prinzipien der Äquivalenz von Trägheit und Schwere.
Spinning Test Particles as Locally Nonrotating Observers in Kerr Spacetime
Authors: Fuchs Helmut
Published: May 2007

We derive a class of exact solutions of Mathisson‐Papapetrou equations of motion for spinning test particles. The world lines of the particles are those of the so‐called locally non‐rotating observers in Kerr spacetime.
On the Migdal‐Makeenko Equation for Simple and Nonsimple Contours
Authors: Otto H. J. , Weigt G.
Published: May 2007

The Migdal‐Makeenko equation differs explicitely in the abelian and nonabelian case for simple smooth contours already. This is due to endpoint singularities of gauge noninvariant functionals which appear in the nonabelian equation providing anomalous finite contributions in the course of renormalization. Corresponding results are discussed for nonsimple contours.
Kinetics of the Ar‐Hg Plasma of Fluorescent Lamp Discharges. I. Model — Basic Equations — Hg Partial Pressure Variation
Authors: Winkler R. B. , Wilhelm J. , Winkler R.
Published: May 2007

A kinetic description of the dc Hg‐Ar mixture plasma of fluorescent lamp discharges is given on the basis of the main microphysical processes and corresponding atomic data. The investigation comprises particle balances for the excited Hg atoms of the triplet 63P0,1,2 and singulet 61P1 state, the balance of the discharge current and an adequate form of the electron Boltzmann equation for such a mixture plasma, the latter including also the various binary collision processes with excited Hg atoms and the Coulomb interaction between the electrons. By simultaneously solving the balances together with the kinetic equation the densities of electrons and excited Hg atoms, the electron energy distribution, the resulting mean energy, mobility and various energy transfer rates of the electrons and the ultraviolet radiation output were determined and in part compared with measured data from the literature. This paper presents and analyses the macroscopic plasma properties mentioned for a wide range of the wall temperature or the corresponding Hg partial pressure variation, where a good agreement of calculated results with experimental data is obtained. In a second paper the change of the macroscopic plasma behaviour due to variation of buffer gas pressure and discharge current will be dealt with.
On the Application of the Spin‐Locking Technique for NMR Self‐Diffusion Measurements by Pulsed Field Gradients
Authors: Germanus A. , Pfeifer H. , Heink W. , Kärger J.
Published: May 2007

A new method for nmr self‐diffusion measurements, the spin‐locking echo technique, is presented. As with the stimulated‐echo technique, its application is recommended for large ratios T1/T2 of the longitudinal and transverse relaxation times. It is shown that the new technique is less sensitive to disturbances due to residual field gradients, thus allowing the determination of smaller self‐diffusion coefficients.
Renormalization and Short Distance Properties of Gauge Invariant Gluonium and Hadron Operators
Authors: Dorn H. , Robaschik D. , Wieczorek E.
Published: May 2007

Various expressions for nonlocal gauge invariant meson, baryon and gluonium operators are considered which differ from one another not only by the colour representations of the phase factors used but also with respect to the underlying contours. Renormalization and short distance properties of these operators turn out to be unique as long as the contours chosen are smooth ones. Anomalous dimensions of mesons and baryons can be expressed in terms of a gauge independent anomalous dimension of the quark field. Furthermore, composite operators distinguished by the absence of renormalization are discussed.
An Extension of the Governing Principle of Dissipative Processes to Nonlinear Constitutive Equations
Authors: Verhás J.
Published: May 2007

A generalisation of Onsager's reciprocal relations has been proved by phenomenological methods. It is pointed out that Gyarmati's variational principle is valid in case of nonlinear constitutive equations, too.
On the Correlations between the Particles in the EPR‐Paradoxon
Authors: Treder H.‐J.
Published: May 2007

The Einstein‐Podolsky‐Rosen “gedanken‐experiment” does not imply non‐local interactions or an “action‐at‐a‐distance”.

Contrary, the EPR proves the measurements at one particle does not have influences at canonical variables of the other particles if the quantum‐mechanical commutation relations are true.

But, the EPR implices correlations between the particles which come in by “subjective knowledge”. These correlations are a priori informations about the relative motion or, complementarily, about the motion of the center of mass. The impression of an action‐at‐a‐distance is produced by the use of usual particle coordinates in the EPR‐arrangements.

The discussion of the Einstein‐Podolsky‐Rosen “gedanken‐experiment” (EPR) has been going on over fifty years. EINSTEIN, PODOLSKY, and ROSEN formulated their famous paradox in 1935, and in the discussion between N. BOHR (1935, 1949) and A. EINSTEIN (1936, 1948); A. EINSTEIN (1948) made his point that the EPR implied an “action‐at‐a‐distance” for quantum‐mechanical particles (without obvious classical interactions). His argument is the starting point for the recent discussion about EPR and causality (see A. Aspect, 1981).