Papers by Silviu-Constantin Sararu
Romanian Journal of Physics, 2013
All consistent self-interactions for a topological BF model with a maximal field spectrum in an a... more All consistent self-interactions for a topological BF model with a maximal field spectrum in an arbitrary spacetime dimension are computed and classified. We use the elegant method of constructing consistent interactions in gauge field theories based on the calculation of the local BRST cohomology under standard hypotheses. The major result is that there appear three main classes of vertices: one involving only A-type forms, another linear in B-like forms, and a third category bilinear in B-like forms. The precise structure of the vertices for a given BF model strongly depends on the spacetime dimension D. The general results are exemplified in detail for D = 7 and D = 8. The self-interacting Lagrangian always stops at order one in the coupling constant, but its consistency at all orders is dictated by a set of algebraic and differential equations restricting the functions that parameterize the self-couplings. The interacting model is shown to describe a highly nontrivial gauge theo...
Consistent interactions for a four-dimensional gauge theory, described in the free limit by an ab... more Consistent interactions for a four-dimensional gauge theory, described in the free limit by an abelian BF-type model and one massive Dirac field, are approached in the framework of the deformation theory based on the local BRST cohomology. The deformation procedure leads to an interacting model with modified gauge transformations, whose algebra is open.
The Dirac bracket for gauge-fixed three-and two-forms with Stueckelberg coupling is derived in an... more The Dirac bracket for gauge-fixed three-and two-forms with Stueckelberg coupling is derived in an irreducible fashion. It is explicitly shown that the results emerging from the irreducible context coincide with those from the reducible treatment.
Nuclear Physics B, 2009
An irreducible canonical approach to second-class constraints reducible of an arbitrary order is ... more An irreducible canonical approach to second-class constraints reducible of an arbitrary order is given. This method generalizes our previous results from [10, 11] for first-and respectively second-order reducible second-class constraints. The general procedure is illustrated on Abelian gauge-fixed p-forms.
Journal of High Energy Physics, 2006
Consistent interactions that can be added to a free, Abelian gauge theory comprising a finite col... more Consistent interactions that can be added to a free, Abelian gauge theory comprising a finite collection of BF models and a finite set of two-form gauge fields (with the Lagrangian action written in firstorder form as a sum of Abelian Freedman-Townsend models) are constructed from the deformation of the solution to the master equation based on specific cohomological techniques. Under the hypotheses of smoothness in the coupling constant, locality, Lorentz covariance, and Poincaré invariance of the interactions, supplemented with the requirement on the preservation of the number of derivatives on each field with respect to the free theory, we obtain that the deformation procedure modifies the Lagrangian action, the gauge transformations as well as the accompanying algebra. The interacting Lagrangian action contains a generalized version of non-Abelian Freedman-Townsend model. The consistency of interactions to all orders in the coupling constant unfolds certain equations, which are shown to have solutions.
Journal of High Energy Physics, 2005
All consistent interactions in five spacetime dimensions that can be added to a free BF-type mode... more All consistent interactions in five spacetime dimensions that can be added to a free BF-type model involving one scalar field, two types of one-forms, two sorts of two-forms, and one threeform are investigated by means of deforming the solution to the master equation with the help of specific cohomological techniques. The couplings are obtained on the grounds of smoothness, locality, (background) Lorentz invariance, Poincaré invariance, and the preservation of the number of derivatives on each field.
Journal of High Energy Physics, 2003
Consistent Hamiltonian interactions that can be added to an abelian free BF-type class of theorie... more Consistent Hamiltonian interactions that can be added to an abelian free BF-type class of theories in any n ≥ 4 spacetime dimensions are constructed in the framework of the Hamiltonian BRST deformation based on cohomological techniques. The resulting model is an interacting field theory in higher dimensions with an open algebra of on-shell reducible first-class constraints. We argue that the Hamiltonian couplings are related to a natural structure of Poisson manifold on the target space.
Nuclear Physics B, 2008
Under the general hypotheses of locality, smoothness of interactions in the coupling constant, Po... more Under the general hypotheses of locality, smoothness of interactions in the coupling constant, Poincaré invariance, Lorentz covariance, and preservation of the number of derivatives on each field, we investigate the cross-couplings of one or several spin-two fields to a massless p-form. Two complementary cases arise. The first case is related to the standard interactions from General Relativity, but the second case describes a new, special type of couplings in D = p + 2 spacetime dimensions, which break the PT-invariance. Nevertheless, no consistent, indirect cross-interactions among different gravitons with a positively defined metric in internal space can be constructed.
Journal of Physics A: Mathematical and Theoretical, 2007
An irreducible canonical approach to second-order reducible secondclass constraints is given. The... more An irreducible canonical approach to second-order reducible secondclass constraints is given. The procedure is exemplified on gauge-fixed three-forms.
International Journal of Modern Physics A, 2006
Starting with a finite collection of Abelian models, all consistent interactions (in n≥4 dimensio... more Starting with a finite collection of Abelian models, all consistent interactions (in n≥4 dimensions) that break the PT invariance are obtained by means of the Hamiltonian deformation procedure based on local BRST cohomology. This paper enhances one of our previous works, where only PT-invariant deformations were considered. The associated coupled theory is an interacting, topological BF model exhibiting an open gauge algebra and on-shell reducibility relations.
International Journal of Modern Physics A, 2004
Consistent interactions that can be added to a two-dimensional, free Abelian gauge theory compris... more Consistent interactions that can be added to a two-dimensional, free Abelian gauge theory comprising a special class of BF-type models and a collection of vector fields are constructed from the deformation of the solution to the master equation based on specific cohomological techniques. The deformation procedure modifies the Lagrangian action, the gauge transformations, as well as the accompanying algebra of the interacting model.
International Journal of Modern Physics A, 2006
Consistent interactions that can be added to a free, Abelian gauge theory comprising a collection... more Consistent interactions that can be added to a free, Abelian gauge theory comprising a collection of BF models and a set of three-form gauge fields are constructed from the deformation of the solution to the master equation based on specific cohomological techniques. Under the hypotheses of smooth, local, PT invariant, Lorentz covariant, and Poincaré invariant interactions, supplemented with the requirement on the preservation of the number of derivatives on each field with respect to the free theory, we obtain that the deformation procedure modifies the Lagrangian action, the gauge transformations as well as the accompanying algebra.
International Journal of Geometric Methods in Modern Physics, 2004
The basic BRST cohomological properties of a free, massless tensor field with the mixed symmetry ... more The basic BRST cohomological properties of a free, massless tensor field with the mixed symmetry of the Riemann tensor are studied in detail. It is shown that any non-trivial co-cycle from the local BRST cohomology group can be taken to stop at antighost number three, its last component belonging to the cohomology of the exterior longitudinal derivative and containing non-trivial elements from the (invariant) characteristic cohomology.
The European Physical Journal C, 2006
The cross-couplings among several massless spin-two fields (described in the free limit by a sum ... more The cross-couplings among several massless spin-two fields (described in the free limit by a sum of Pauli-Fierz actions) in the presence of a massive Rarita-Schwinger field are investigated in the framework of the deformation theory based on local BRST cohomology. Under the hypotheses of locality, smoothness of the interactions in the coupling constant, Poincaré invariance, Lorentz covariance, and the preservation of the number of derivatives on each field, we prove that there are no consistent cross-interactions among different gravitons with a positively defined metric in internal space in the presence of a massive Rarita-Schwinger field. The basic features of the couplings between a single Pauli-Fierz field and a massive Rarita-Schwinger field are also emphasized.
The European Physical Journal C, 2005
The couplings of a collection of BF models to matter theories are addressed in the framework of t... more The couplings of a collection of BF models to matter theories are addressed in the framework of the antifield-BRST deformation procedure. The general theory is exemplified in the case where the matter fields are a set of Dirac spinors and respectively a collection of real scalar fields.
The European Physical Journal C, 2009
Under some plausible assumptions, we find that the dual formulation of linearized gravity in D = ... more Under some plausible assumptions, we find that the dual formulation of linearized gravity in D = 5 can be nontrivially coupled to the topological BF model in such a way that the interacting theory exhibits a deformed gauge algebra and some deformed, on-shell reducibility relations. Moreover, the tensor field with the mixed symmetry (2, 1) gains some shift gauge transformations with parameters from the BF sector.
The European Physical Journal C, 2004
Non-trivial, consistent interactions of a free, massless tensor field t µν|αβ with the mixed symm... more Non-trivial, consistent interactions of a free, massless tensor field t µν|αβ with the mixed symmetry of the Riemann tensor are studied in the following cases: self-couplings, cross-interactions with a Pauli-Fierz field and cross-couplings with purely matter theories. The main results, obtained from BRST cohomological techniques under the assumptions on smoothness, locality, Lorentz covariance and Poincaré invariance of the deformations, combined with the requirement that the interacting Lagrangian is at most second-order derivative, can be synthesized into: no consistent self-couplings exist, but a cosmologicallike term; no cross-interactions with the Pauli-Fierz field can be added; no non-trivial consistent cross-couplings with the matter theories such that the matter fields gain gauge transformations are allowed.
The European Physical Journal C, 2008
The local and manifestly covariant Lagrangian interactions in four spacetime dimensions that can ... more The local and manifestly covariant Lagrangian interactions in four spacetime dimensions that can be added to a free model that describes a massless Rarita-Schwinger theory and an Abelian BF theory are constructed by means of deforming the solution to the master equation on behalf of specific cohomological techniques.
Annalen der Physik, 2006
The proof of the fact that there are no nontrivial, consistent crosscouplings that can be added b... more The proof of the fact that there are no nontrivial, consistent crosscouplings that can be added between the Weyl graviton and the massless Rarita-Schwinger field is accomplished by means of a cohomological approach, based on the deformation of the solution to the master equation from the antifield-Becchi-Rouet-Stora-Tyutin (BRST) formalism. The procedure developed here relies on the assumptions of locality, smoothness, (background) Lorentz invariance, Poincaré invariance, and preservation of the number of derivatives with respect to each field (the last hypothesis was made only in antighost number zero).
Annalen der Physik, 2003
The local and manifestly covariant Lagrangian interactions in four spacetime dimensions that can ... more The local and manifestly covariant Lagrangian interactions in four spacetime dimensions that can be added to a "free" model that describes a generic matter theory and an abelian BF theory are constructed by means of deforming the solution to the master equation on behalf of specific cohomological techniques.
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Papers by Silviu-Constantin Sararu