Four‐dimensional couplings among BF and matter theories from BRST cohomology

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.     

Cohomological derivation of the couplings between an abelian gauge field and matter fields

Consistent couplings between an abelian gauge field and a system of matter fields are investigated by means of Lagrangian cohomological arguments.     

Irreducible Freedman‐Townsend vertex and Hamiltonian BRST cohomology

The irreducible Freedman‐Townsend vertex is derived by means of the Hamiltonian deformation procedure based on local BRST cohomology.     

Synthesis of new 10,11-dihydrodibenzo[a,d]cycloheptene S-thiocarbamate derivatives via a benzylic Newman–Kwart rearrangement

New S-thiocarbamates possessing a 10,11-dihydro-5H-dibenzo[a,d]cycloheptene moiety were obtained unexpectedly in the process of preparing new O-thiocarbamates starting from 5-dibenzosuberol (10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ol) and aroyl-isothiocyanates. These compounds were obtained via a benzylic Newman–Kwart rearrangement mechanism. The structures of the new thiocarbamates were confirmed by elemental analysis, IR, and NMR spectroscopy and by X-ray crystallography.     

Four-dimensional couplings among BF and massless Rarita–Schwinger theories: a BRST cohomological approach

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 using specific cohomological techniques.     

Valence states of iron ions in nanostructured yttrium iron garnet Y3Fe5O12 studied by means of soft X-ray absorption spectroscopy

Nanostructured samples of yttrium iron garnet Y₃Fe₅O₁₂ obtained by plastic deformation method (high-pressure torsion) were studied with help of soft X-ray absorption spectroscopy using Fe 2p and O 1s spectra. Experimental spectra were compared with crystal field multiplet calculations for Fe ions. Some amount of Fe²⁺ ions in nanostructured Y₃Fe₅O₁₂ was found. The concentration of Fe²⁺ ions was found to be increased with the increase of the degree of plastic deformation.     

Consistent interactions of dual linearized gravity in <Emphasis Type="Italic">D</Emphasis>=5: couplings with a topological BF model

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.     

No interactions for a collection of spin-two fields intermediated by a massive Rarita–Schwinger field

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.PACS 11.10.Ef     

Couplings of a collection of BF models to matter theories

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.Received: 7 September 2004, Revised: 21 March 2005, Published online: 18 May 2005PACS: 11.10.Ef     

Interactions for a collection of spin-two fields intermediated by a massless p-form

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$D=p+2$ 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.