1,261 research outputs found

    Absolute conservation law for black holes

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    In all 2d theories of gravity a conservation law connects the (space-time dependent) mass aspect function at all times and all radii with an integral of the matter fields. It depends on an arbitrary constant which may be interpreted as determining the initial value together with the initial values for the matter field. We discuss this for spherically reduced Einstein-gravity in a diagonal metric and in a Bondi-Sachs metric using the first order formulation of spherically reduced gravity, which allows easy and direct fixations of any type of gauge. The relation of our conserved quantity to the ADM and Bondi mass is investigated. Further possible applications (ideal fluid, black holes in higher dimensions or AdS spacetimes etc.) are straightforward generalizations.Comment: LaTex, 17 pages, final version, to appear in Phys. Rev.

    Universal conservation law and modified Noether symmetry in 2d models of gravity with matter

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    It is well-known that all 2d models of gravity---including theories with nonvanishing torsion and dilaton theories---can be solved exactly, if matter interactions are absent. An absolutely (in space and time) conserved quantity determines the global classification of all (classical) solutions. For the special case of spherically reduced Einstein gravity it coincides with the mass in the Schwarzschild solution. The corresponding Noether symmetry has been derived previously by P. Widerin and one of the authors (W.K.) for a specific 2d model with nonvanishing torsion. In the present paper this is generalized to all covariant 2d theories, including interactions with matter. The related Noether-like symmetry differs from the usual one. The parameters for the symmetry transformation of the geometric part and those of the matterfields are distinct. The total conservation law (a zero-form current) results from a two stage argument which also involves a consistency condition expressed by the conservation of a one-form matter ``current''. The black hole is treated as a special case.Comment: 3

    Induced wormholes due to quantum effects of spherically reduced matter in large N approximation

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    Using one-loop effective action in large N and s-wave approximation we discuss the possibility to induce primordial wormholes at the early Universe. An analytical solution is found for self-consistent primordial wormhole with constant radius. Numerical study gives the wormhole solution with increasing throat radius and increasing red-shift function. There is also some indication to the possibility of a topological phase transition.Comment: LaTeX file, 2 eps figures, 9 pages, few misprints are corrected, numerics are change

    35-jährige Patientin mit generalisiertem Krampfanfall und nicht-kardiogenem Lungenödem nach Intoxikation

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    Zusammenfassung: Nach Intoxikation mit Verapamil-Retardpräparaten sind verzögerte und prolongierte kardiovaskuläre Nebenwirkungen bekannt. Wir berichten über 2 seltene Nebenwirkungen in Form eines generalisierten Krampfanfalls und eines nicht-kardiogenen Lungenödems, welche erst 13 bzw. 48h nach der Intoxikation aufgetreten sind. Aufgrund der verzögert auftretenden und prolongierten Arzneimittelwirkungen muss bei Intoxikationen mit retardierten Kalziumantagonisten die gastrointestinale Dekontamination mit antegrader Darmspülung und anschließender Aktivkohletherapie auch bei initial symptomfreien Patienten bis mindestens 24h nach Intoxikation gefordert werde

    Comment on: ``Trace anomaly of dilaton coupled scalars in two dimensions''

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    The trace anomaly for nonminimally coupled scalars in spherically reduced gravity obtained by Bousso and Hawking (hep-th/9705236) is incorrect. We explain the reasons for the deviations from our correct (published) result which is supported by several other recent papers.Comment: 2 page

    Two-dimensional effective action for matter fields coupled to the dilaton

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    We revise the calculation of the one-loop effective action for scalar and spinor fields coupled to the dilaton in two dimensions. Applying the method of covariant perturbation theory for the heat kernel we derive the effective action in an explicitly covariant form that produces both the conformally invariant and the conformally anomalous terms.For scalar fields the conformally invariant part of the action is nonlocal. The obtained effective action is proved to be infrared finite. We also compute the one-loop effective action for scalar fields at finite temperature.Comment: LaTeX, 25 page

    A Vector Supersymmetry in Noncommutative U(1) Gauge Theory with the Slavnov Term

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    We consider noncommutative U(1) gauge theory with the additional term, involving a scalar field lambda, introduced by Slavnov in order to cure the infrared problem. we show that this theory, with an appropriate space-like axial gauge-fixing, wxhibits a linear vector supersymmetry similar to the one present in the 2-dimensional BF model. This vector supersymmetry implies that all loop corrections are independent of the λAA\lambda AA-vertex and thereby explains why Slavnov found a finite model for the same gauge-fixing.Comment: 18 pages, 3 figures; v2 Acknowledgments adde
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