bluuebunny/crossref_metadata_2025 huggingface dataset:
Zur Berechnung des geodätischen Abstands und assoziierter Invarianten im relativistischen Gravitationsfeld
Authors: John R. W.
Published: May 2007

Die Berechnung der Weltfunktion in Riemannscher Raum‐Zeit ‐
das ist im wesentlichen das Quadrat des geodätischen Abstands zweier Ereignisse ‐, die durch ein System nichtlinearer Differentialgleichungen bestimmt ist, wird im statischen kugelsymmetrischen Fall auf ein Quadratur‐ und Eliminationsproblem reduziert. Danach folgt die symmetrieangepaßte Konstruktion weiterer Invarianten der Raum‐Zeit, die sich aus Ableitungen der Weltfunktion zusammensetzen. Anwendung der gewonnenen Fundamentalgleichungen auf spezielle Scharen von Modell‐Metriken, die als Einsteinsche Gravitationspotentiale interpretiert werden, gibt explizite strenge Resultate für die betrachteten Zweipunkt‐Skalare.
Sea Level Muon Spectrum Derived from the All Particle Primary Spectrum of GRIGOROV et al.
Authors: Bhattacharyya D. P.
Published: May 2007

The all particle primary spectrum of GRIGOROV et al. surveyed by HILLAS has been fitted by a power law fit of the form
Iall particle(>E) = 1.3 E−1.65 (cm2 s sr)−1
where E is the energy in GeV/nucleus. Using our recently determined conversion factor for protonnuclei flux ratio of equal energies the primary proton spectrum has been calculated and the result agrees with the Goddard Space Flight Centre primary proton spectrum data satisfactorily. The primary nucleon spectrum has also been calculated and follows the form
Nnucleons(E) dE = 2.664 E−2.75 dE (cm2 s sr GeV/nucleon)−1.

Using this primary nucleon spectrum as the source of hadrons and accelerator data for various inclusive reactions viz. used for the estimation of hadronic energy moments in the frame work of FEYNMAN‐
Scaling, the differential meson spectra have been estimated. The meson atmospheric diffusion equation after Bugaev et al. has been considered for the derivation of sea level muon spectrum. The magnetic spectrograph data of Allkofer et al., Ayre et al., Green et al., and MUTRON group are in accord with the calculated muon spectrum.
Covariant Quantization of Spinor Fields in a Given Gravitational Field
Authors: Kreisel Eckhard
Published: May 2007

In coupling gravity with the quantum field theory, unitary transformations, depending on space‐time‐points, were considered and derivatives were introduced, which imply a nonintegrable parallel transport of the state vectors of Hilbert space [1]. The Dirac equation, built with these generalized derivatives, is quantized in a prescribed classical gravitational field. The quantization can be performed in complete analogy to the usual procedure in Minkowski space, but the quantum state vector becomes path dependent. In carrying out the quantization, two two‐component classical spinor fields necessarily occur, which obey Weyl's equation. The considered quantized Dirac equations are also picture‐covariant, that is they have the same from in each physical picture, especially in the Heisenberg picture and the Schrödinger picture.
Zur Ganggeschwindigkeit von Uhren auf der rotierenden Erde
Authors: Richter Gustav
Published: May 2007

ALBERT EINSTEINS Bemerkung von 1905, daß eine am Erdäquator aufgestellte Unruh‐Uhr etwas langsamer liefe als eine gleichartige, an einem der Erdpole befindliche Uhr, wird durch einen entgegenwirkenden Gravitationseffekt gerade aufgehoben, so daß alle an beliebigen Orten auf Meeresniveau befindlichen Uhren gleichschnell gehen: Die kinematische Zeitverzögerung der mit der Erddrehung bewegten Uhr erweist sich als genau entgegengesetzt gleich der Gangbeschleunigung derselben Uhr durch den Gravitationseffekt auf dem „Äquatorwulst”︁ der Erde.

Ferner werden das sog. Uhrenparadoxon und das Hafele‐Keating‐Experiment in einer etwas anderen als der meist üblichen Weise diskutiert.
Search for the Neutral Dibaryon with Strangeness −2 in High Transverse Momentum π− Nucleus Interactions at 40 GeV/c
Authors:   RISK collaboration, Bärwolff H. , Friebel W. , Gensch U. , Kundt U. , Lanius K. , Roloff H. , Schreiber H. J. , Denes E. , Diosy L. , Gemesy T. , Jenik L. , Krasnovsky J. , Pinter Gy. , Wagner I. , Bannikov A. V. , Böhm J. , Grishkevich Ya. V. , Khomenko B. A. , Krumstein Z. V. , Merekov Yu. P. , Petrukhin V. I. , Safarik K. , Shelkov G. A. , Tkachev L. G. , Vertogradov L. S. , Soukup T. , Valkarova A. , Valkar S. , Zavada P. , Penev V. N. , Sklovskaja A. I. , Jarishvili A. K. , Kharchillava A. I. , Lomtadze T. A. , Razdolskaya L. A. , Dominik W. , Gajewski J. , Majewski S. , Pniewska K. , Ropelewski L. , Zakrzewski J. A.
Published: May 2007

Analysing high transverse momentum π− nucleus interactions at 40 GeV/c, a search has been made for the hypothetical dibaryon H0 with strangeness −2, spin‐parity 0+ and mass below the two lambda mass. The data came from an experiment performed with a streamer chamber which is well suited to find the H0 through its unique signature of the weak p decay. No H0 event has been found. The 90% confidence upper limit for the observed frequency of production of the H° dibaryon per inelastic π−A collision amounts to 1.5 ·10−4. Cross section upper limits are estimated for C, Cu and Pb targets, also with 90% confidence level.
Trends in Nonlinear Optics
Authors: Fischer R. , Schubert M.
Published: May 2007

A review is given on some of the most important nonlinear optical phenomena. We discuss different fields of application as well as problems of more fundamental character. In particular we shall concentrate on short‐wavelength generation, multiphoton processes of very high order, nonlinear optical processes in dielectric waveguides, measurement of subpicosecond pulses, determination of second‐ and first‐order radiation functionals, optical bistability, nonlinear processes and noise reduction in optical communication systems, and nonlinear optical processes as potential ways for producing squeezed states.
Nachweis eines optischen Gewinns nach UV‐Mehrphotonendissoziation von Molybden‐Hexacarbonyl
Authors: Grunwald R. , Hertz J. H.
Published: May 2007

Berichtet wird über den Nachweis einer optischen Verstärkung, die bei Mehrphotonen‐Dissoziation von Molybden‐Hexacarbonyl auftritt, und die vorwiegend auf neutrale Molybden‐Atome zurückgeführt wird. Als Anregungsquelle diente ein XeCl‐Laser (308 nm; 25 MW). Mit einer Zylinderlinsen‐Anordnung konnten Fluoreszenzzonen variabler Länge erzeugt und die Verstärkung der axialen Emission zeitaufgelöst gemessen werden.
The Problem of Electric Sources in Einstein's Hermite‐symmetric Field Theory
Authors: Kreisel Eckhard
Published: May 2007

It is considered, if a geometric source breaks the A‐invariance and Hermite‐symmetry of Einstein's Hermitian relativity. It would be very meaningful to interpret a source of this kind as electric current. With this extension Einstein's unitary field theory contains electromagnetism and the gluonic vacuum of chromodynamics.
Kooperative spontane Emission von zwei ungleichen Atomen
Authors: Richter Th.
Published: May 2007

Es werden die totale Intensität, die Winkelverteilung der abgestrahlten Energie und Photonenkorrelationen der kooperativen spontanen Strahlung von zwei Atomen mit verschiedenen Resonanzfrequenzen und spontanen Zerfallsraten berechnet. Im Gegensatz zu zwei identischen Atomen treten in der totalen Intensität Oszillationen auf und weicht die Winkelverteilung der insgesamt emittierten Photonen von der Ein‐Atom‐Richtcharakteristik ab. Der Einfluß der Dipol‐Dipol‐Nahfeldwechselwirkung auf die zeitliche Entwicklung des Atomsystems wird diskutiert.
Newtons „Principia Mathematica Philosophia”︁ und Plancks Elementarkonstanten
Authors: Rompe R. , Treder H.‐J.
Published: May 2007

Die Newtonschen Prinzipien, zusammen mit den Planckschen Elementarkonstanten, erweisen sich als gesichertes Fundament der Physik und der „exakten”︁ Wissenschaften aller Richtungen.

Der Begriffsfundus der Physik ist ausreichend für alle physikalischen aber auch weiterreichenden Probleme anderer Naturwissenschaften und Technik. Es zeigt sich, daß die klassische Physik von vornherein so angelegt wurde, daß sie über die Physik der makroskopischen Körper weit hinaus‐greifen kann.
Sinn und Möglichkeiten der Theoretischen Physik. Zum 300. Jahrestag von Newtons „Philosophiae Naturalis Principia Mathematica”︁
Authors: Rompe R. , Thiessen P. A. , Treder H.‐J.
Published: May 2007

Die Newtonschen Prinzipien und die aus ihnen gewonnene Erkenntnis der Existenz von Elementarkonstanten nach Planck, Einstein und Bohr erweisen sich zunehmend als tragfähiges Fundament nicht nur der Physik und ihrer Anwendung in der Technik, sondern überhaupt aller „exakten”︁ Wissenschaften in breitestem Sinne des Wortes.

Die physikalisch inhaltliche Klärung der Begriffe erfolgt seit Newton in engem Verbund mit der Entwicklung mathematischer Methoden. Diese Kombination erweist sich weiterhin als produktiv und sichert den Fortschritt der Physik und der „exakten”︁ Wissenschaften.

Wohl alle Probleme, die im Bereich der Technik Bedeutung haben können, lassen sich bei entsprechendem Aufwand bereits mit dem vorhandenen Fundus an Erkenntnissen und Methoden erfolgreich angehen.

Der in der Wirklichkeit verankerte Zusammenhang von Gesetz und Zufall erweist sich als eine Manifestation der Dialektik in der Natur. „Es gibt keinen absoluten Zufall”︁. Sie kommt in allen Zweigen der Physik, nicht nur in der Thermodynamik und Quantenphysik, zutage, und muß bereits auf dem Niveau der Newtonschen Prinzipien und der Elementarkonstanten behandelt werden.

Die theoretische Physik, so wie sie von Newton initiiert worden ist, wurde so angelegt, daß sie alle Seiten der Wirklichkeit, so weit sie in die Kompetenz der Physik fallen, umfaßt. Es besteht darum kein Gegensatz zwischen der klassischen Physik und der Quantenphysik. Es handelt sich lediglich um eine Differenzierung nach den unterschiedlichen physikalischen Inhalten und den angemessenen mathematischen Methoden, die natürlich von der Wahl der Probleme abhängen.

Die theoretische Physik stellt eine allgemein zugängliche Zusammenfassung des gesicherten Wissens der Physik dar, das zugleich das Fundament der „exakten”︁ Wissenschaften ist.

Die theoretische Physik ist damit das Mittel der Verständigung innerhalb der Kooperation, die notwendig ist zur Lösung der großen komplexen Aufgaben der Wissenschaft und Technik.
Newtons Theorie der Schallgeschwindigkeit
Authors: Schöpf H.‐G.
Published: May 2007

Newtons Theorie der Schallgeschwindigkeit wird werkgetreu im modernen Stil kritisch erläutert.
Der experimentelle Stand der Anomalonen‐Forschung
Authors: Ganssauge Eberhard
Published: May 2007

Es wird ein Überblick über den derzeitigen Stand (Oktober 1986) der experimentellen Anomalonenforschung gegeben. Die verschiedenen Meßmethoden, Kernspuremulsionstechnik, Silberchlorid‐, Einkristall‐, Plastik‐, Čerenkovzähler‐ und Blasenkammerexperimente werden einander gegenübergestellt und ihre Ergebnisse verglichen, wobei den AgCl‐Detektoren und der SCHOPPERschen Auswerteapparatur eine besondere Bedeutung für die zukünftige Forschung auf diesem Gebiet zuerkannt wird.

Dem Computertrend folgend erscheinen diejenigen Methoden, die mit elektronischer Datenauswertung arbeiten, wie Plaistkdetektoren, Čerenkovzähler und der „Crystallball”︁ — unkritisch bewertet — aufgrund ihrer hohen Datenmenge den direkten Meßmethoden, wie Kernspuremulsionen und AgCl‐Einkristallen, eindeutig überlegen. Ein bislang vorwiegend negatives Resultat dieser elektronischen Methoden bezüglich des Anomaloneneffektes, der im ersten Kapitel beschrieben wird, kann in dessen äußerst komplexer Natur bei geringer Ionisationsausbeute liegen. So deuten beispielsweise eine Reihe von Emulsionsmessungen darauf hin, daß er vorwiegend in „weißen”︁ Sternen (Nh= 0) auftritt. Das könnte eventuell erklären, weshalb diejenigen Emulsionsgruppen, die sehr unempfindliche Emulsionen benutzen, kein positives Ergebnis erbringen können. Zu bedenken sind u.a. die physikalischen Parameter für den ungeklärten Umstand, daß z.B. dieselbe Emulsionsgruppe den Effekt bei einem Projektil der EnergieEeinmal sieht, bei einem anderen Projektil derselben Energie jedoch nicht findet. Es erscheint notwendig, systematisch von anderer Seite nach weiteren Charakteristika der Anomalonen zu suchen. Die neue radiochemische Methode scheint ein interessanter Vorstoß in diese Richtung zu sein. Es wäre wünschenswert, die Bemühungen um eine Automatisierung der Emulsionsmethode weiter voranzutreiben, insbesondere Arbeiten zu unterstützen, die auf diesem Wege bereits geleistet worden sind. Einige Gedanken dazu sind im Schlußkapitel wiedergegeben.

Die umfangreiche theoretische Literatur konnte nur kurz gestreift werden, obwohl sie teilweise hochinteressante Ideen liefert.

Insgesamt kann dieser Bericht nur den Anspruch eines Zwischenberichtes erheben; er zeigt gerade, daß die Anomalonenforschung noch ziemlich am Anfang steht.
The Variational Approach to the Scalar Field Theory in Curved Einstein Space
Authors: Mańka R. , Kuczyński J.
Published: May 2007

The variational approach based on the covariant quantization method for the curved Einstein space is applied.
Bäcklund Transformation and N‐Soliton Solution for the Generalized Nonlinear Schrödinger Equation
Authors: Eichhorn H.
Published: May 2007

For the generalized nonlinear Schrödinger equation, the N‐fold Bäcklund transformation is derived. As particular results, the explicit 1‐soliton solution is obtained and the interaction of two solitons is discussed.
On the Light‐Cone Expansion in Gauge Field Theories (QED)
Authors: Bordag M. , Kaschluhn L.
Published: May 2007

The techniques for the derivation of light‐cone expansions in scalar field theories are generalized to nonscalar, especially gauge field theories. For this reason the smallness of the remainder is proved in an arbitrary renormalizable theory provided an infrared regularization is present. Then we apply the formalism to derive a light‐cone expansion for the product of two scalar currents in Quantum Electrodynamics in leading order. Thereby the gauge‐invariance of the underlying theory is used from the very beginning by the application of the known solutions of the Ward identities. As a result of that, one obtains two gauge‐invariant light cone operators, and the corresponding coefficient functions are independent one from another.
Photoakustische Messung der Absorption an einem Ensemble dichtgepackter kugelförmiger Absorber
Authors: Walther Heinz‐Günter
Published: May 2007

Unter Benutzung des Rosencwaig‐Gersho‐Modells wurde das photoakustische Absorptionssignal von einem Ensemble dichtgepackter kugelförmiger Absorber bei Berücksichtigung der Lichtstreuung in der Probe berechnet. Die theoretischen Resultate wurden mit Meßergebnissen verglichen, die an hochbrechenden Mikroglaskugeln (Ballotini) erhalten wurden. Aus den Fittungsbedingungen sind Aussagen zur Absorption der nichtkompakten Probe möglich.
Condensate Structure of the Vacuum of Quantum Chromodynamics
Authors: Herrmann J.
Published: May 2007

The non‐perturbative vacuum structure of quantum chromodynamies (QCD) is studied with the help of methods which are generalizations of those used to describe condensation effects and quasi‐particles in superfluid and superconductive mediums. The gluon condensation is explained by the introduction of a new vacuum state defined by a Bogoljubov transformation, leading to non‐vanishing vacuum expectation values as e.g. the gluon condensation parameter, a negative vacuum energy density, and to a gap in the energy spectrum which is connected with excited quasi‐particle states with a rest mass.
On Static Asymptotically Flat Solutions of Fourth Order Gravitational Field Equations
Authors: Schmidt H.‐J.
Published: May 2007

It is shown that each non‐flat regular static asymptotically flat solution of the gravitational field equation following from the Lagrangian

has in a certain sense positive energy. Further, for a set of parameters including the BACH‐EINSTEIN theory

some results concerning the full nonlinear behaviour of the solutions of the field equation will be given.
Die Lorentz‐Transformation als Ausdruck der Superposition gegenläufiger Raum‐Zeit‐Beziehungen, Preisgabe des Relativitätsprinzips
Authors: Renninger M.
Published: May 2007

Jegliche Erhöhung der Eigenenergie eines mit einer Uhr ausgestatteten Objekts, ΔE = E — E0 (wobei E0 die Ruhenergie) ist verbunden mit einer Erhöhung seiner Zeitablaufgeschwindigkeit, t/t0 = E/E0 (EINSTEIN 1907). Faktische Beobachtung dieses beschleunigenden Einflusses auf die Ganggeschwindigkeit jeder an der Energieerhöhung teilhabenden Uhr ist auf denjenigen durch Erhöhung der potentiellen Energie beschränkt. Energieerhöhung in Form von kinetischer Energie \documentclass{article}\pagestyle{empty}\begin{document}$ \left({E/E_0 {\rm = }1/\sqrt {1 - \frac{{v^2 }}{{c^2 }}} } \right) $\end{document} ist im Gegenteil mit einer Verlangsamung des Zeitgangs verbunden, einer Verlangsamung von genau demselben, d.h. invers gleich großen, durch die Lorentz‐Transformation bestimmten Betrag \documentclass{article}\pagestyle{empty}\begin{document}$ \left({t/t_0 \, = \,\sqrt {1 - \frac{{v^2 }}{{c^2 }}} } \right) $\end{document}, dem Betrag der relativistischen „Zeitdilatation”︁, des „Transversalen Dopplereffekts”︁. Die Lorentz‐Transformation ist eine ausschließlich kinematische Aussage, ohne Beziehung zu der mit jeder Bewegung verbundenen Energieerhöhung.

Anbetrachts des Fehlens jedes vernünftigen Grunds, warum der zeitbeschleunigende Einfluß von Energieerhöhung im Fall von kinetischer Energie fehlen sollte, erscheint seine Berücksichtigung unerläßlich. Der faktische, den Zeitgang verlangsamende Effekt \documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt {1 - \frac{{v^2 }}{{c^2 }}} $\end{document} muß daher als eine Superposition des gangbeschleunigenden Energieeffekts \documentclass{article}\pagestyle{empty}\begin{document}$ 1/\sqrt {1 - \frac{{v^2 }}{{c^2 }}} $\end{document} und eines invers „doppelt”︁ so großen kinematischen Effekts (1 — v2/c2) angesetzt werden.

Es werden modifizierte Transformationsgleichungen hergeleitet, die dieser Forderung nach Unterteilung der tatsächlichen Raum‐Zeit‐Beziehungen Rechnung tragen, deren „integrale”︁ Form jedoch identisch ist mit der klassischen Lorentz‐Transformation, dann, wenn ausschließlich kinetische Energie ins Spiel kommt.

Natürlich steht diese Unterteilung des Sinngehalts der Transformationsgleichungen im Widerspruch zum Relativitätsprinzip, sie setzt die Existenz eines in bezug auf das Universum absolut ruhenden Systems voraus. Eine Reihe von Argumenten wird vorgebracht, welche die Vorstellung von einem solchen Absolut‐System faszinierender erscheinen lassen als die geläufige von der Gleichwertigkeit aller Inertialsysteme.
Hartree‐Fock Energies of the Doubly Excited States of the Boron Isoelectronic Sequence
Authors: El‐Sherbini Th. M. , Mansour H. M. , Farrag A. A. , Rahman A. A.
Published: May 2007

Hartree‐Fock energies of the 1s2 2s 2p ns(4P), 1s2 2s 2p np(4P, 4D) and 1s2 2s 2p nd(4P, 4D); n = 3–6 states in the boron isoelectronic sequence are reported. The results show a fairly good agreement with the experimental data of Bromander for O IV.
Über Volumendefekte und Krümmung bei der Robertson‐Walker‐Metrik und Konstruktion kosmologischer Modelle
Authors: Gackstatter Fritz
Published: May 2007

Für die Robertson‐Walker‐Metrik werden Riemannsche Normalkoordinaten konstruiert und der zugehörige Krümmungstensor berechnet. Anschließend werden die in [3] gewonnenen Ergebnisse über Volumendefekte und Krümmung bei der R‐W‐Metrik und bei Spezialfällen dieser Metrik, die kosmologische Modelle darstellen, angewandt. Schließlich werden kosmologische Modelle konstruiert, die verschiedene Entwicklungsstufen unseres Kosmos: p ≈ 0, 1/3 u, 2/3 u, einheitlich beschreiben. Die Friedmannschen Gleichungen werden mit Hilfe eines Laurentreihenansatzes für Energiedichte u und Druck p gelöst.
On the Origin of Spacetime Distribution of Quasars II. The Modified Model
Authors: Popić R. V.
Published: May 2007

The theory of quasar production in collisions of massive black holes with galaxies is developed. The distribution of number of quasars N with respect to the cosmological redshift Z is calculated and a fair agreement with observational data is obtained. The predictive power of the theory to explain a set of observational effects is discussed.
On the Direct Generation of Electricity from Heat in Plasmas via a Self‐Organization Process
Authors: Psimopoulos M.
Published: May 2007

By combining the Nernst effect with the law of Ampere, it is shown that if a temperature gradient is present in a plasma, an electric current can be self‐sustained due to the transformation of thermal into electromagnetic field energy. We call the configuration in which the above phenomenon occurs the “thermomagnetic battery” and study its steady state operation for an infinite slab geometry assuming that the plasma is fully ionized and the magnetic field is weak (ωeτe ≪ 1) so that the heat flow is mainly transferred by electrons.
In Favor of a Newtonian Quantum Gravity
Authors: Diósi L. , Lukács B.
Published: May 2007

We list arguments for creating a unified theory of Newtonian Gravity and Quantum Mechanics. This nonrelativistic level has been historically bypassed, however even here one is confronted with conceptional problems anticipating some features of Relativistic Quantum Gravity. Bearing in mind Wigner's famous analysis on measurabilitity in the relativistic case here a genuine uncertainty of the Newton potential is verified, leading to the breakdown of the Schrödinger equation when leaving microscopic regions.
Linear Motion under Constant Force and Radiation Reaction
Authors: Sen Gupta N. D.
Published: May 2007

The classical relativistic equation of motion with radiation reaction is solved exactly when the motion is along the lines of force due to a constant electric field. For physically admissible solutions, there is no contribution due to the radiation reaction. The general motion without radiation reaction is not linear.
A Class of Solutions of Non‐Linear Evolution Equations with Diffusion
Authors: Enders P.
Published: May 2007

The technique of generating functions developed by WILHELMSSON [1] for the diffusion equation with quadratic recombination term is improved to yield overall exact (special) solutions and discussed with respect to higher‐order non‐linearity. Some applications of our results are mentioned.
On the D.C.‐Limit of the Electric Conductivity of Plasmas
Authors: Blümlein J.
Published: May 2007

A continued fraction of type 2N is used to solve the d.c.‐problem for the electrical conductivity of plasmas. The coupling parameter dependence of the expansion coefficients is determined. It is shown that this technique allows to derive different order collision times for dilute systems.
The Hadamard Construction of Green's Functions on a Curved Space‐Time with Symmetries
Authors: John R. W.
Published: May 2007

The Hadamard constituents of Green's functions for a ζ‐parametrized generalization of the massless scalar d'Alembert equation to a curved space‐time including the conformally invariant wave equation: the world function of space‐time, the transport scalar, and the tail‐term coefficients, being simultaneously coefficients in the Schwinger‐DeWitt expansion of the Feynman propagator for the corresponding invariant Klein‐Gordon equation, are considered on a general static spherically symmetric and (2,2)‐decomposable metric. The construction equations determining the Hadamard building elements are cast into a symmetry‐adapted form and used to obtain, on a specific model metric, exact explicit solutions.
Systems with Hysteresis in an Extremely Slowly Fluctuating Environment
Authors: Jetschke G.
Published: May 2007

Systems exhibiting hysteresis are considered in an extremely slowly fluctuating environment. The parameter causing the hysteresis is assumed to be a Markovian diffusion process elapsing much more slowly than the internal dynamics. The infinitesimal generator for the resulting Markov process including the hysteresis jumps is derived and explicit expressions for the probability densities are given. A numerical example shows the change from monomodal to bimodal behaviour of the stationary distribution if the variance of the external noise increases representing a new kind of noise‐induced transition.
On Construction and Solution of the Fifth‐Order Korteweg‐de Vries Equation
Authors: Murawski K.
Published: May 2007

The Lax's criterion has an attempt at construction of the fifth‐order Korteweg‐de Vries equation. One‐soliton solution of this equation is obtained via using the inverse scattering technique.
Zur Entstehung des Schallstrahlungsdruckes
Authors: Richter G.
Published: May 2007

Der Schallstrahlungsdruck in Flüssigkeiten und Gasen wird unter Benutzung der Bernoullischen Gleichung der Schallbewegung in der Näherung kleiner Amplituden erneut diskutiert, wobei einige Ableitungen vereinfacht und verkürzt wurden. Insbesondere wird der von G. Hertz und H. Mende erstmals beobachtete „negative Schallstrahlungsdruck”︁ näher betrachtet.
Über neue Erscheinungen beim Haidingerschen Büschel und seine neue Erklärung
Authors: Mo K.‐W.
Published: May 2007

Es werden drei neue Erscheinungen im Zusammenhang mit dem Haidingerschen Büschel beschrieben, die zum Erkennen seines Wesens führen. Eine neue Erklärung wird entwickelt, die mit den Beobachtungen weitgehend übereinstimmen.
Schrödinger's Interpretation of Ψ as a Continuous Charge Distribution
Authors: Barut A. O.
Published: May 2007

Radiation theory is reformulated by reviving the interpretation of Ψ‐waves as realistic material waves of electronic matter and the relation of this formulation to second quantized quantum field theory is discussed.
Zu den Einstein‐Schrödingerschen Feldgleichungen mit Materie
Authors: Treder Hans‐Jürgen
Published: May 2007

Die physikalische Bedeutung des Materietensors in der unitären Feldtheorie von Einstein und Schrödinger wird diskutiert.
Demokrit und die Quantenmechanik
Authors: Wahsner Renate
Published: May 2007

Es wird gezeigt, daß der antike Atomismus ein auch für die moderne Physik fundamentales Denkprinzip begründete, ein Prinzip, das es in seiner Newtonschen Modifizierung ermöglicht, die Bewegung und das Kontinuum physikalisch zu fassen.
Painleve Analysis and the Yang‐Mills Equation in Two Specific Cases
Authors: Chowdhury A. Roy , Naskar Minati
Published: May 2007

Two important configurations of Yang‐Mills fields are discussed applying to them the Painleve test of Ablowitz. The case with a constant electric E‐field does not admit an exact solution while the cylindrically symmetric self‐dual system admits an inverse scattering approach for instanton solution.
A Theoretical Study on Irregular Emission Properties in Lasers Coupled to a Long External Resonator
Authors: Müller R. , Glas P.
Published: May 2007

Irregular intensity patterns have been generated numerically in a model consisting of coupled resonators including an extra bandwidth‐limiting element. The emission properties in the lasing state considered are characterized by complex‐plane representations of the field amplitude especially by a stroboscopic map. Characteristic features of the output pulses are analyzed by calculated power spectrum, autocorrelation function, and attractor dimension. Low‐frequency components, anticorrelated behavior, and a low‐dimensional strange attractor have been found revealing the chaotic nature of the dynamic behavior of the system studied.
Topological Geometrodynamics
Authors: Pitkänen M.
Published: May 2007

The identification of spacetime as a 4‐surface in the space H =M4×CP2 (product of Minkowski space and complex projective space of complex dimension two) as means of obtaining Poincare invariant theory of gravitation was the triggering idea of topological geometrodynamics (TGD), which can be regarded as an attempt to unify basic interactions in terms of submanifold geometry instead of abstract manifold geometry as in case of General Relativity. One can however regard TGD also as a generalization of string model: instead of strings free particles are regarded as 3‐surfaces. In this article I want to describe these two approaches and to show how they merge into a single coherent scheme provided macroscopic 3‐space with matter is identified as a 3‐surface containing particles as topological inhomogenities. Also the quantization program of TGD based on the idea that interacting field theory can be regarded as a classical, free field theory for Grassmann algebra valued Schrödinger amplitude in the space of all possible 3‐surfaces of H, is described.
Unser griechisches Erbe
Authors: Schöpf Hans‐Georg
Published: May 2007

Es wird dargelegt, daß fundamentale Konzeptionen der Physik auf die griechische Naturphilosophie zurückgeführt werden können, speziell auf Pythagoreismus, Platonismus und auf den Atomismus Demokrits. Am Ende des Artikels wird ein kurzer Blick auf den Zusammenhang zwischen Aristotelismus und Physik geworfen.
Black Holes and Inflation
Authors: González‐Díaz P. F.
Published: May 2007

A model for black hole collapse and evaporation in which the black hole is supposed to be an excited state of one of the Planck black holes pervading the structure of spacetime is discussed. By assuming a Coleman‐Weinberg gravitational effective potential for a scalar field inside the collapse matter, it is shown that the black hole state cannot be attained neither through bubble tunneling nor by the rolling down of the field.
On Some Solutions of Relativistic Wave Equations
Authors: Ternov I. M. , Khapaev A. M. , Ponomaryov I. V.
Published: May 2007

In this paper we present exact solutions of the Klein‐Gordon and the Dirac equations in different configurations of an electromagnetic field, which are characteristic for free‐electron laser‐type gauges. In the case of motion of a charge scalar particle in standing wave an energy spectrum is studied. For the motion of an electron in a so‐called wiggler magnetic field a spinor wave function is proved to be obtainable. An undulator field configuration with propagating wave is treated also.
Can We See SPT Interactions in Coherent Pion Production?
Authors: Rein D.
Published: May 2007

The possibility to detect nonconventional scalar, pseudoscalar or tensor interactions (SPT) in the angular distribution of pions produced coherently in neutrino nucleus reactions is reexamined. It is found that the angular distribution does not differ qualitatively from a corresponding distribution arising from conventional VA interactions unless the energy of the outgoing pion is restricted. Even then SPT interactions are likely to be overshadowed by transverse VA interactions which can mimic the former at finite although small momentum transfer Q2.
Bound Three Alpha Particles Model for the 12C Nucleus as a Three‐Body Problem
Authors: Osman Ahmed , Farag M. Y. H.
Published: May 2007

The alpha cluster model is used in the description of the 12C nucleus. This model introduces the 12C nucleus as composed of bound three alpha particles. According to this model, the 12C nucleus is studied as a three‐body problem. Three‐body integral equations are obtained by using non local separable potentials for the nuclear alpha‐alpha interactions. The separable two‐body interactions used, consist of both attraction and repulsion. The alpha‐alpha interactions are taken to be of the Gaussian potential form. The different parameters of the alpha‐alpha interaction are obtained by fitting the corresponding alpha‐alpha phase shifts. The different form factors are calculated. Also, numerical calculations of the resulting three‐body integral equations are carried out to obtain the binding energy of this bound state. The theoretically calculated value of the binding energy of the 12C nucleus as bound three‐alpha particles is in good agreement with experimental value.
Four Momentum Transfer between the Fireballs in Carbon‐Emulsion Interaction at 4.5 GeV/c per Nucleon
Authors: Ghosh D. , Sengupta R. , Roy J.
Published: May 2007

This paper presents an analysis of the four momentum transfer between the fireballs in the events produced in 12C‐Emulsion interaction at 4.5 GeV/c per nucleon. The results have been compared with the predications of the Pomeranchuk Pole exchange model.
On the Semiclassical Quantization of the Chiral Soliton
Authors: Reinhardt H.
Published: May 2007

The soliton of the effective chiral action of QCD is quantized in a semiclassical fashion using the “cranking approach” developed for the description of rotating nuclei. It is shown that for the Skyrmion model this approach is equivalent to the semiclassical quantization proposed by Adkins et al. Contrasting the assumptions of the cranking approach to the experimental excitation spectrum of the nucleon leads to the conclusion that the semiclassical quantization is inapplicable to the chiral soliton if the latter is to describe the physical nucleon.
New Converging Collimator for Cold Neutrons Time‐Of‐Flight Measurements
Authors: Naguib K. , Sallam O. H. , Salama Mohamed
Published: May 2007

An idea to design a new converging collimator for cold neutron time‐of‐flight measurements is presented. Using this new facility in combination with a neutron time‐of‐flight spectrometer, we may have neutron intensity gain factors about three times that obtained using the conventional straight slit collimators. Expressions for calculating the collimators dimensions as well as the intensity gain and the time resolution broading were presented.
Introduction of Anomalous Green Functions into Quantum Chromodynamics
Authors: Herrmann J.
Published: May 2007

The nonperturbative vacuum structure of Quantum Chromodynamic is studied with the help of a generalization of the formalism of Green functions which corresponds to the method of Gorkov and Nambu in the theory of superconductivity. Taking into account the existence of gluon condensation the selfenergy of the gluon‐quasi‐particles is calculated with the help of modified rules for Feynman diagrams. The resulting integral equations for the effective field parameters contain particular solutions with an energy gap in the spectrum of the quasi‐particles and a phase transition at a critical momentum.
Gamma Dose Distribution Studies in Ducted Shield Material Having Different Configurations
Authors: Ahmed F. M. Sayed
Published: May 2007

In the present work the radial distribution of total gamma doses arising from the interaction of reactor neutrons and gamma radiations inside ilmenite heavy concrete shield are measured. The ilmenite concrete is pierced with neutral beam injector ducts having different diameters and lengths. The results obtained show a relative increase in radial gamma doses at a distance of 10 cm from the neutral beam end. An empirical formula was obtained, fitting the measured gamma doses at the peak position in good agreement within a factor of 1.27. Moreover the variation of the total gamma radiation was measured along straight filled ducted with different diameters and length. The experimental data obtained show a reasonable agreement with calculated ones. The scattered as well as unscattered components of the gamma radiation transmitted through a straight duct were investigated. An empirical formula describing this behaviour was obtained.
Classical Elementary Particle Models Based on the Dualistic Approach
Authors: Mahanta M. N. , Gupta Y. K.
Published: May 2007

In conformity with ideas of the recent dualistic approach to gravitation of the author classical heuristic models of nucleons and electrons are constructed. The numerical values computed for the different parameters turn out to be realistic although because of their static character the models as such cannot quite represent reality.
Electric Dipole Oscillator Strength and Radiative Lifetimes in the Magnesium Isoelectronic Sequence
Authors: El‐Sherbini Th. M. , Mansour H. M. M. , Farag A. A. , Rahman A. A.
Published: May 2007

Oscillator strengths for the singlet 3sns(1S)‐3smp(1P); (n, m = 3‐7), 3snp(1P)‐3smd(1D); (n = 4‐7, m = 3‐6) and the triplet 3sns(3S)‐3smp(3P); (n = 4‐7, m = 3‐7), 3snp(3P)‐3smd(3D); (n = 4‐7, m = 3‐6) transitions in the Mg I sequence are calculated in LS‐coupling scheme. The Coulomb approximation is used in calculating the radial part of the wave functions, while the angular part is determined using the Racah technique. Lifetimes of the upper 3sns(3S, 1S); (n = 4‐7) and 3snp(3P, 1P); (n = 3‐7) excited states are obtained and compared with the available experimental data.
Topological Properties of String‐Solutions of Einstein's Unified Field Theory
Authors: Kreisel Eckhard
Published: May 2007

If in Antoci's solution [7] of Einstein‐Schrödingers unified systems of equations the spacetime is equipped with Diraec's string topology, then the solution fulfills everywhere the Einstein‐Schrödinger equations and the quark charges are of topological origin, For the pseudo‐Hermitian theory the zero of the determinant of the metric is considered.
Zur Geschichte der Bohr‐Sommerfeldschen Quantentheorie
Authors: Schöpf Hans‐Georg
Published: May 2007

In der vorliegenden Arbeit werden Artikel von N. Bohr, P. Ehrenfest, A. Sommerfeld, P. Epstein und K. Schwarzschild im Hinblick auf die wesentlichen Konzeptiontionen in der Geschichte der älteren Quantentheorie im Zeitraum von 1914 bis 1918 besprochen.
Solar Anisotropy of Muon Component of Cosmic Rays
Authors: Bishara A. A. , Darwish A. A.
Published: May 2007

Cosmic‐ray underground observations are used together with the difference coupling coefficients to determine, by spectrographic method, features of the differential energy spectrum of solar anisotropy of cosmic rays. The differential energy spectrum is found to have a constant form up to an upper effective rigidity boundary which changes with solar activity.
Monte Carlo simulation of overdamped motion in a double well potential under the influence of coloured noise
Authors: Müller Judith , Schnakenberg Jürgen
Published: May 2007

We present a Monte Carlo simulation algorithm for evaluating the stationary probability and the mean and the variance of first passage times in any dynamical system under the influence of additive coloured Gaussian and Marcovian noise (Ornstein‐Uhlenbeck process). Our algorithm generates the Ornstein‐Uhlenbeck process by a superposition of a finite number of random telegraph processes. We obtain our results from a direct evaluation of the trajectories. We apply our method to the overdamped motion of a particle in a double well potential. We compare our simulation results with various analytic approximations for the stationary probability and the mean first passage times.
Magnetization of disordered ballistic quantum billards
Authors: Braun Daniel , Gefen Yuval , Montambaux Gilles
Published: May 2007

We study the magnetic response of mesoscopic quantum dots in the ballistic regime where the mean free path le is larger that the size L of the sample, yet smaller than L(KFL)d−1. In this regime, disorder plays an important role. Employing a semiclassical picture we calculate the contribution of long tranjectories which are strongly affected by static disorder and which differ sharply from those of clean systems. In the case of a magnetic field, they give rise to a large linear paramagnetic susceptibility (which is disorder independent), whose magnitude is in agreement with recent experimental results. In the case of a Aharonov‐Bohm flux, the susceptibility is disorder dependent and is proportional to the mean free path as in the diffusive regime. We also discuss the corresponding non‐linear susceptibilities.
Towards a theory of the integer quantum Hall transition: From the nonlinear sigma model to superspin chains
Authors: Zirnbauer Martin R.
Published: May 2007

A careful study of the supersymmetric version of Pruisken's nonlinear σ model for the integer quantum Hall effect is presented. The lattice regularized model is cast in Hamiltonian form by taking the anisotropic limit and interpreting the topological density as an alternating sum of Wess Zumino terms. It is argued that the relevant large‐scale physics of the model is preserved by projection of the quantum Hamiltonian on its sector of degenerate strong‐coupling ground states. For values of the Hall conductivity close to e2/2h (mod e2/h), where a delocalization transition occurs, this yields the Hamiltonian of a quantum superspin chain which is closely related to an anisotropic version of the Chalker‐Coddington model. The relation implies that the ratio of magnetic length over potential correlation length is an irrelevant parameter at the transition. The superspin chain resembles a 1 d isotropic antiferromagnet with spin 1/2. It has an alternating structure which however permits an invariance under translation by one site. The conductance coefficients of a quantum Hall system with N small contacts translate into N‐superspin correlation functions which are governed by conformal invariance. The superspin formalism provides a framework for studying the crossover from classical to quantum percolation. It does not however encompass the frequency‐dependent correlations of wave amplitudes at criticality.
Dielectric dispersion of ferroelectric ceramics and single crystals at microwave frequencies
Authors: Arlt G. , Böttger U. , Witte S.
Published: May 2007

The dielectric constant of ferroelectric ceramics shows strong Debye‐like relaxation at GHz frequencies. This relaxation is caused by sound generation inside the crystallites. The ferroelastic domain walls which vibrate in the electric ac field are very effective shear wave transducers. The shear wave emission has a maximum when the wavelength of the sound wave is comparable to the width of the domains. Above this frequency the domain walls can no longer vibrate due to inertia and do not contribute to the dielectric constant. The observed dependence of the microwave dispersion on temperature, doping and grain size of the ferroelectric ceramic is in good agreement with the proposed mechanism of the emission of acoustic shear waves.
Relaxation of translational energy in binary mixtures of dense hard sphere systems
Authors: Cukrowski A. S. , Fritzsche S. , Haberlandt R.
Published: May 2007

Starting from the Enskog equation we derive an analytical equation for the relaxation time necessary for the equilibration between translational energies of the components in a dense binary mixture of hard spheres. Also we give an expression for the collision number describing the average number of collisions of one particle during the relaxation time. The analytical expressions are verified by molecular dynamics simulations for various values of the packing fraction. The results are shown to be valid even for very dense systems, i.e. for liquids in the ranges of density corresponding to the freezing point.
Acoustic wavefront imaging
Authors: Wolfe J. P. , Hauser M. R.
Published: May 2007

We introduce a new class of experiments which provide graphic insights into the propagation of acoustic waves in anisotropic media. Simply stated, we have devised a means of observing the expanding acoustic wavefront from a point disturbance in a solid. The data may be viewed as a movie or a series of snapshots. The observed wavefronts represent the group‐velocity surfaces of acoustic waves, which reflect the basic elastic anisotropy of the solid. The technique has been applied to coherent acoustic waves with frequencies in the megahertz range (at ambient temperatures) and to incoherent heat pulses in the hundred‐gigahertz range (at liquid‐helium temperatures). In this article, we first provide a pedagogical introduction to wave propagation in elastically anisotropic media, reviewing some early methods for visualizing acoustic waves. Next, we describe the “acoustic wavefront imaging” method and give representative results in crystals and composite materials. Finally, we show how this method relates to recent advances in phonon imaging and internal diffraction of ultrasound.
The influence of thin helium films on the phonon spectrum of optically excited silicon
Authors: Türk F. , Ullrich G. , Kinder H.
Published: May 2007

We have studied the phonon spectra resulting from laser pulse excitation of a silicon surface. We used a phonon spectrometer based on pressure tuned boron levels in silicon (Si: B‐spectrometer). A new design allowed us to use the spectrometer in vacuum for the first time. We observed phonon frequencies up to 1 THz. The pulse shapes indicated both, quasidiffusion and a long exciton lifetime. On adding helium films to the surface we have found dramatic changes of the spectrum. Full thermalisation was reached already at a thickness of 1.5 monolayers. This indicates a strong anharmonic interaction in the very first monolayers at these high frequencies and, in addition, a strong confinement of the phonons to the surface by quasidiffusion.
Frequency multiplication of microwave radiation in a semiconductor superlattice by electrons capable to perform Bloch oscillations
Authors: Grenzer J. , Schomburg E. , Ignatov A. A. , Renk K. F. , Pavel'ev D. G. , Koschurinov Yu. , Melzer B. Ja. , Ivanov S. , Schaposchnikov S. , Kop'ev P. S.
Published: May 2007

We report the observation of frequency multiplication of microwave radiation in a GaAs/AlAs semiconductor superlattice at room temperature. We observed, for a fundamental frequency of 9 GHz, second and third harmonic generation. We associate the harmonic generation with a nonlinear current‐voltage characteristic that is determined by Bloch oscillations of electrons propagating along the superlattice axis. Our results suggest for the frequency multiplication an upper limit in the tetrahertz frequency range.
On the waves and instability in self‐gravitating magnetic molecular clouds with ambipolar diffusion Part 1: Planar modal approach
Authors: Yue Z. Y. , Zhang B. , Winnewisser G. , Stutzki J.
Published: May 2007

It is well established that molecular clouds are the main sites of active star formation in our Galaxy. The interaction of the three major physical agents in molecular clouds, i.e. the self‐gravity, magnetic fields, and ambipolar diffusion, in the form of waves and instability, governs the dynamics and evolution of molecular clouds. The present work is a new effort on this subject.

This work consists of two parts. In Part 1, we complete the planar modal analysis by removing the restrictions on the direction of the velocity perturbation which were used in previous studies. Thus, the wave number vector k is allowed to take any direction with respect to the mean field B0. The exact general dispersion relation is found to be a seventh‐order equation and can be reduced to a quartic equation as the first approximation about the small parameter xρ = ρi, 0/ρn,0, the density ratio between ions and neutrals. The growth rate contour maps in the k plane are obtained for various values of the basic dimensionless parameters Λ and σ, where Λ = VA,n/Cn is the ratio between the Alfvén speed and the sound speed in the neutrals, and the “coupling factor” σ = vi/ωg,n is the ratio between the average collision frequency of a neutral with ions and the self‐gravitation response frequency. It is shown that, in all directions, magnetic field only reduces the growth rate but does not change the critical wave length for instability. The reduction of the growth rate depends on not only Λ, the dimensionless measure of the field strength, but also the direction of k as well as the coupling factor σ. The frequencies and the dissipation rates of the Alfvén waves and the fast and slow self‐gravitating magnetosonic waves are calculated for all directions of k. The solutions of these waves are also given.

Although the planar modal approach is important in understanding the basic mechanism of magnetic waves and instability, it does not take into account the three‐dimensionality and the finite size of the cloud and is therefore only suitable to the local analysis. Thus, in order to discuss the global properties, we will develop a cylindrical modal approach in Part 2. There, we will also discuss certain nonlinear effects and show their importance in leading to a self‐adjusting mechanism which slows down the global collapse at the early stage of cloud evolution and refreshes the outward propagating Alfvén and fast magnetosonic waves caused by star‐forming or core‐forming activities. In this way, a significant portion of the released gravitational energy during the global collapse is turned into the magnetic waves to support the cloud against the global collapse itself.