75 research outputs found

    QED Revisited: Proving Equivalence Between Path Integral and Stochastic Quantization

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    We perform the stochastic quantization of scalar QED based on a generalization of the stochastic gauge fixing scheme and its geometric interpretation. It is shown that the stochastic quantization scheme exactly agrees with the usual path integral formulation.Comment: 11 page

    Global Path Integral Quantization of Yang-Mills Theory

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    Based on a generalization of the stochastic quantization scheme recently a modified Faddeev-Popov path integral density for the quantization of Yang-Mills theory was derived, the modification consisting in the presence of specific finite contributions of the pure gauge degrees of freedom. Due to the Gribov problem the gauge fixing can be defined only locally and the whole space of gauge potentials has to be partitioned into patches. We propose a global path integral density for the Yang-Mills theory by summing over all patches, which can be proven to be manifestly independent of the specific local choices of patches and gauge fixing conditions, respectively. In addition to the formulation on the whole space of gauge potentials we discuss the corresponding global path integral on the gauge orbit space relating it to the original Parisi-Wu stochastic quantization scheme and to a proposal of Stora, respectively.Comment: 8 pages, Latex, extended versio

    Quantizing Yang-Mills Theory: From Parisi-Wu Stochastic Quantization to a Global Path Integral

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    Based on a generalization of the stochastic quantization scheme we recently proposed a generalized, globally defined Faddeev-Popov path integral density for the quantization of Yang-Mills theory. In this talk first our approach on the whole space of gauge potentials is shortly reviewed; in the following we discuss the corresponding global path integral on the gauge orbit space relating it to the original Parisi-Wu stochastic quantization scheme.Comment: 4 pages, Latex, uses espcrc2.sty; talk by Helmuth Huffel at the Third Meeting on Constrained Dynamics and Quantum Gravity, Villasimius, Sardinia, Italy, Sept. 13-17, 199

    Generalized Stochastic Quantization of Yang-Mills Theory

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    We perform the stochastic quantization of Yang-Mills theory in configuration space and derive the Faddeev-Popov path integral density. Based on a generalization of the stochastic gauge fixing scheme and its geometrical interpretation this result is obtained as the exact equilibrium solution of the associated Fokker--Planck equation. Included in our discussion is the precise range of validity of our approach.Comment: 19 pages, Late

    Transition Amplitudes within the Stochastic Quantization Scheme

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    Quantum mechanical transition amplitudes are calculated within the stochastic quantization scheme for the free nonrelativistic particle, the harmonic oscillator and the nonrelativistic particle in a constant magnetic field; we close with free Grassmann quantum mechanics.Comment: 14 pages, LaTeX, UWThPh-1993-23 and DPUR 6

    Generalized Stochastic Gauge Fixing

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    We propose a generalization of the stochastic gauge fixing procedure for the stochastic quantization of gauge theories where not only the drift term of the stochastic process is changed but also the Wiener process itself. All gauge invariant expectation values remain unchanged. As an explicit example we study the case of an abelian gauge field coupled with three bosonic matter fields in 0+1 dimensions. We nonperturbatively prove quivalence with the path integral formalism.Comment: 6 pages, latex, no figure

    Nonlinear Phenomena in Canonical Stochastic Quantization

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    Stochastic quantization provides a connection between quantum field theory and statistical mechanics, with applications especially in gauge field theories. Euclidean quantum field theory is viewed as the equilibrium limit of a statistical system coupled to a thermal reservoir. Nonlinear phenomena in stochastic quantization arise when employing nonlinear Brownian motion as an underlying stochastic process. We discuss a novel formulation of the Higgs mechanism in QED.Comment: 8 pages, invited talk at the International Workshop ``Critical Phenomena and Diffusion in Complex Systems'', Dec. 5-7, 2006, Nizhni Novgorod, Russi

    Structure and function of the skin of Tylototriton verrucosus (Anderson, 1971) with special emphasis on cutaneous glands

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    T. verrucosus besitzt mindestens drei unterschiedliche Typen von multizellulären Hautdrüsen. Diese Drüsen liegen eingebettet in die Dermis und besitzen Ausführgängen, die durch die Epidermis reichen und sich nach außen hin öffnen. Schleimdrüsen sind die kleinsten aller Hautdrüsen und homogen über den Körper verteilt. Sie sind verantwortlich für die Produktion von einem Gemisch aus vor allem neutralen Mukopolysacchariden. Das zentrale Lumen ist von einem einschichtigen sekretorischen Epithel umgeben, welches die Sekrete für den schlüpfrigen Schleimfilm bereitstellt, der den Amphibienkörper bedeckt und mehrere wichtige Funktionen übernimmt. Die übrigen zwei Hautdrüsentypen zählen zu den seröse Drüsen und werden auch als Giftdrüsen bezeichnet. Sie unterscheiden sich von Schleimdrüsen in mehreren morphologischen Kriterien und in ihren histologischen Färbungseigenschaften. An manchen Körperstellen, besonders in den Parotoiden und im dorsalen Schwanzbereich treten solche Giftdrüsen sehr konzentriert und stark vergrößert auf. Als Anpassung im Zuge der Feindabwehr werden durch spezielle Körperhaltungen gerade jene Bereiche Feinden entgegengestellt. In der Haut von T. verrucosus konnten zwei unterschiedliche Typen von Giftdrüsen identifiziert werden. Typ 1 (GG1) ist am gesamten Körper zu finden, während Typ 2 (GG2) auf den Schwanzbereich begrenzt ist und gigantische Drüsendurchmesser von 1550 µm erreichen kann. Basierend auf Ergebnisse dieser Studie in Kombination mit Erkenntnissen aus der Literatur kann man davon ausgehen, dass beide Typen gesundheitsschädliche bis giftige Chemikalien produzieren, die bei einem Zusammentreffen mit Feinden eingesetzt werden um diese abzustoßen. Morphologische Erkenntnisse von Schleim- und Giftdrüsen und Ergebnisse histologischer Färbungen gaben Aufschluss über ihre möglichen Funktionsweisen. In Folge der konstanten Notwendigkeit eines oberflächendeckenden Schleimfilms entlassen Schleimdrüsen ihre Sekrete fortwährend auf eine vor allem merokrine Art und Weise. Sie sind bei Juvenilen und Adulten gleich ausgeprägt und besitzen vermutlich einen regelmäßigen und ständig ablaufenden Regenerationszyklus. In diesem Prozess vermehren sich Zellen von apical nach basal und ersetzen dabei absterbende Zellen. Im Gegensatz zu Schleimdrüsen, ist die Ausprägung von Giftdrüsen bei Juvenilen und Adulten unterschiedlich. Deren Reifung ist durch lang dauernde biochemische Prozesse charakterisiert. Reife Giftdrüsen sind generell aus sehr vielen, großen Zellen aufgebaut, die gefüllt sind mit Sekret. Ausgereifte Giftdrüsen sind organellenarme Strukturen, die auf einen Zustand eingestellter Aktivität hinweisen. Folglich stehen in reifen Drüsen die Sekrete fertig bereit um bei Bedarf ausgestoßen zu werden. Ein deutlich ausgeprägtes und gut entwickeltes Myoepithel, welches die gesamte Drüse umgibt ist bei T. verrucosus vorhanden. Dessen Muskelkontraktionen gewährleisten eine schnelle Ausscheidung der Drüseninhalte, als effektiven Schutz gegen Fressfeinde.T. verrucosus shows at least three different multicellular cutaneous gland types, embedded in the dermis with ducts that open through the epidermis to the exterior. Mucous glands (MG) are the smallest glands, homogenously distributed throughout the body. They are responsible for producing an assortment of mainly neutral mucopolysaccharids. MGs are build up by a layer of secretory cells, encircling a central lumen and provide the secretions of the slippery mucus film that covers the body, generally participated in several crucial functions. The latter two gland types are serous in nature and differ in several morphological and histostaining properties from MGs. They are big and especially enlarged in areas of glandular accumulations, most conspicuous in the parotoids and the tail dorsum. Notably these areas with enlarged granular gland concentrations are used against aggressor in defensive postures and can be regarded as antipredator adaptations. In the skin of T. verrucosus two different types of GGs were identified. GG1s are present throughout the skin whereas GG2s are restricted to the tail, reaching giant diameters up to 1550 µm. Based on the findings of this study, added to the findings from the literature, both granular gland types are supposed to produce noxious to toxic chemicals deployed during encounter behavior to repel predators. Morphological and histostaining findings of both mucous and granular glands indicated their particular functionalities. Mucous glands mainly release their secretion in a merocrine way, due to the constant necessity of a surface covering mucus film. MGs are similar in juveniles and adults and probably have a regular regeneration process. In this process, cells continuously proliferate from apical to basal and replace dying cells. In contrast to MGs, the appearance of granular glands differs between juveniles and adults. Their maturation is characterized by long biosynthetic and maturational processes during the growth of granular glands. Mature granular glands are huge organelle-poor structures pointing to a state of suspended activity. They are build up by several huge cells, filled with secretion and the glandular contents are stored ready for expulsion. A fast expulsion, for effective defense, is provided by muscular contraction of a well-developed myoepithelial sheath, encircling the gland, a conspicuous characteristic of granular glands in T. verrucosus

    QCD Pressure and the Trace Anomaly

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    Exact relations between the QCD thermal pressure and the trace anomaly are derived. These are used, first, to prove the equivalence of the thermodynamic and the hydrodynamic pressure in equilibrium in the presence of the trace anomaly, closing a gap in previous arguments. Second, in the temporal axial gauge a formula is derived which expresses the thermal pressure in terms of a Dyson-resummed two-point function. This overcomes the infrared problems encountered in the conventional perturbation-theory approach.Comment: 9 pages plain te

    Der Journalisten-Report II - Österreichs Medienmacher und ihre Motive. Eine repräsentative Befragung.: Ein Buch von Andy Kaltenbrunner, Matthias Karmasin, Daniela Kraus, Astrid Zimmermann

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    Verlag: facultas.wuv Erscheinungsort: Wien Erscheinungsdatum: 200
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