155 research outputs found

    Boundary charges in gauge theories: using Stokes theorem in the bulk

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    Boundary charges in gauge theories (like the ADM mass in general relativity) can be understood as integrals of linear conserved n-2 forms of the free theory obtained by linearization around the background. These forms are associated one-to-one to reducibility parameters of this background (like the time-like Killing vector of Minkowski space-time). In this paper, closed n-2 forms in the full interacting theory are constructed in terms of a one parameter family of solutions to the full equations of motion that admits a reducibility parameter. These forms thus allow one to apply Stokes theorem without bulk contributions and, provided appropriate fall-off conditions are satisfied, they reduce asymptotically near the boundary to the conserved n-2 forms of the linearized theory. As an application, the first law of black hole mechanics in asymptotically anti-de Sitter space-times is derived.Comment: 17 pages Latex file, improved presentation, main results unchanged, additional section on first law, additional reference

    A note on the BRST cohomology of the extended antifield formalism

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    The relevance of the BRST cohomology of the extended antifield formalism is briefly discussed along with standard homological tools needed for its computation.Comment: 10 pages Latex file, Proceedings of the spring school "Q.F.T., Supersymmetry and Superstrings" in Calimanesti, Romania, April 199

    Refining the anomaly consistency condition

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    In the extended antifield formalism, a quantum BRST differential for anomalous gauge theories is constructed. Local BRST cohomological classes are characterized, besides the form degree and the ghost number, by the length of their descents and of their lifts, and this both in the standard and the extended antifield formalism. It is shown that during the BRST invariant renormalization of a local BRST cohomological class, the anomaly that can appear is constrained to be a local BRST cohomological class with a shorter descent and a longer lift than the given class. As an application of both results, a simple approach to the Adler-Bardeen theorem for the non abelian gauge anomaly is proposed. It applies independently of the gauge fixing, of power counting restrictions and does not rely on the use of the Callan-Symanzik equation.Comment: 20 pages RevTex fil

    Black hole entropy from non-proper gauge degrees of freedom: II. The charged vacuum capacitor

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    The question which degrees of freedom are responsible for the classical part of the Gibbons-Hawking entropy is addressed. A physical toy model sharing the same properties from the viewpoint of the linearized theory is a charged vacuum capacitor. In Maxwell's theory, the gauge sector including ghosts is a topological field theory. When computing the grand canonical partition function with a chemical potential for electric charge in the indefinite metric Hilbert space of the BRST quantized theory, the classical contribution originates from the part of the gauge sector that is no longer trivial due to the boundary conditions required by the physical set-up. More concretely, in the benchmark problem of a planar charged vacuum capacitor, we identify the degrees of freedom that, in the quantum theory, give rise to an additional contribution to the standard black body result proportional to the area of the plates, and that allow for a microscopic derivation of the thermodynamics of the charged capacitor.Comment: 27 pages, V2: improved discussion of thermodynamics in section 2, references added, no other change

    Higher order cohomological restrictions on anomalies and counterterms

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    Using a regularization with the properties of dimensional regularization, higher order local consistency conditions on one loop anomalies and divergent counterterms are given. They are derived without any a priori assumption on the form of the BRST cohomology and can be summarized by the statements that (i) the antibracket involving the first order divergent counterterms, respectively the first order anomaly, with any BRST cocycle is BRST exact, (ii) the first order divergent counterterms can be completed into a local deformation of the solution of the master equation and (iii) the first order anomaly can be deformed into a local cocycle of the deformed solution.Comment: 11 pages Latex file, mistake in assumption 2 forces a version limited to one loop considerations with a different derivation of main result

    A general non renormalization theorem in the extended antifield formalism

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    In the context of algebraic renormalization, the extended antifield formalism is used to derive the general forms of the anomaly consistency condition and of the Callan-Symanzik equation for generic gauge theories. A local version of the latter is used to derive sufficient conditions for the vanishing of beta functions associated to terms whose integrands are invariant only up to a divergence for an arbitrary non trivial non anomalous symmetry of the Lagrangian. These conditions are independent of power counting restrictions and of the form of the gauge fixation.Comment: 25 pages Latex file, major revision and extensio

    Centrally extended BMS4 Lie algebroid

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    We explicitly show how the field dependent 2-cocycle that arises in the current algebra of 4 dimensional asymptotically flat spacetimes can be used as a central extension to turn the BMS4 Lie algebra, or more precisely, the BMS4 action Lie algebroid, into a genuine Lie algebroid with field dependent structure functions. Both a BRST formulation, where the extension appears as a ghost number 2 cocyle, and a formulation in terms of vertex operator algebras are introduced. The mapping of the celestial sphere to the cylinder then implies zero mode shifts of the asymptotic part of the shear and of the news tensor.Comment: 17 pages Latex file, typos corrected in version

    The Coulomb solution as a coherent state of unphysical photons

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    In the context of the problem of what micro-states are responsible for the entropy of black holes, we consider as a physical toy model the electromagnetic Coulomb solution. By quantizing the electromagnetic field in the presence of an external source of charge Q, the quantum state corresponding to the Coulomb solution is identified as a coherent state of longitudinal and temporal photons in a Hilbert space with negative norm states.Comment: 5 pages Latex file, Proceedings of the 2nd School on Quantum Gravity and Quantum Geometry, Corfu 2009. Cosmetic changes, agrees with version to be published

    Notes on the BMS group in three dimensions: II. Coadjoint representation

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    The coadjoint representation of the BMS3_3 group, which governs the covariant phase space of three-dimensional asymptotically flat gravity, is investigated. In particular, we classify coadjoint BMS3_3 orbits and show that intrinsic angular momentum is free of supertranslation ambiguities. Finally, the link with induced representations upon geometric quantization is discussed.Comment: 22 pages, references added, accepted for publication in JHEP. v3: Minor typos corrected, matches published versio

    Isomorphisms between the Batalin-Vilkovisky antibracket and the Poisson bracket

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    One may introduce at least three different Lie algebras in any Lagrangian field theory : (i) the Lie algebra of local BRST cohomology classes equipped with the odd Batalin-Vilkovisky antibracket, which has attracted considerable interest recently~; (ii) the Lie algebra of local conserved currents equipped with the Dickey bracket~; and (iii) the Lie algebra of conserved, integrated charges equipped with the Poisson bracket. We show in this paper that the subalgebra of (i) in ghost number −1-1 and the other two algebras are isomorphic for a field theory without gauge invariance. We also prove that, in the presence of a gauge freedom, (ii) is still isomorphic to the subalgebra of (i) in ghost number −1-1, while (iii) is isomorphic to the quotient of (ii) by the ideal of currents without charge. In ghost number different from −1-1, a more detailed analysis of the local BRST cohomology classes in the Hamiltonian formalism allows one to prove an isomorphism theorem between the antibracket and the extended Poisson bracket of Batalin, Fradkin and Vilkovisky.Comment: 36 pages Latex fil
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