88 research outputs found
Monopoles for Gravitation and for Higher Spin Fields
We consider massless higher spin gauge theories with both electric and
magnetic sources, with a special emphasis on the spin two case. We write the
equations of motion at the linear level (with conserved external sources) and
introduce Dirac strings so as to derive the equations from a variational
principle. We then derive a quantization condition that generalizes the
familiar Dirac quantization condition, and which involves the conserved charges
associated with the asymptotic symmetries for higher spins. Next we discuss
briefly how the result extends to the non linear theory. This is done in the
context of gravitation, where the Taub-NUT solution provides the exact solution
of the field equations with both types of sources. We rederive, in analogy with
electromagnetism, the quantization condition from the quantization of the
angular momentum. We also observe that the Taub-NUT metric is asymptotically
flat at spatial infinity in the sense of Regge and Teitelboim (including their
parity conditions). It follows, in particular, that one can consistently
consider in the variational principle configurations with different electric
and magnetic masses.Comment: 24 page
<i>Vibrio coralliilyticus</i> sp. nov., a temperature-dependent pathogen of the coral <i>Pocillopora damicornis</i>
Vibrio sp. YB1T (=ATCC BAA-450T =LMG 20984T), the aetiological agent of tissue lysis of the coral Pocillopora damicornis, was characterized as a novel Vibrio species on the basis of 16S rDNA sequence, DNA-DNA hybridization data (G+C content is 45·6 mol%), AFLP and GTG5-PCR genomic fingerprinting patterns and phenotypic properties, including the cellular fatty acid profile. The predominant fatty acids were 16 : 0 and 18 : 1?7c. The name Vibrio coralliilyticus sp. nov. is proposed for the novel coral-pathogenic species. In addition to strain YB1T, which was isolated from the Indian Ocean, five additional strains of V. coralliilyticus have been isolated, three from diseased P. damicornis in the Red Sea, one from diseased oyster larvae (Kent, UK) and one from bivalve larvae (Brazil). The six V. coralliilyticus strains showed high genotypic and phenotypic similarities and all were pathogenic to P. damicornis. The closest phylogenetic neighbours to V. coralliilyticus are Vibrio tubiashii, Vibrio nereis and Vibrio shilonii</i
Caenibacterium thermophilum is a later synonym of Schlegelella thermodepolymerans
Recently, two strains of Schlegelella thermodepolymerans Elbanna et al. 2003 and an
independently isolated bacterium, Caenibacterium thermophilum Manaia et al. 2003, were
described in parallel as gen. nov., sp. nov. Analysis of the 16S rRNA genes revealed similarity
between C. thermophilum and the two strains of S. thermodepolymerans of 99?8 and 99?6%,
respectively. DNA–DNA hybridization experiments revealed mean DNA reassociation levels of
97–98% among C. thermophilum and the two strains of S. thermodepolymerans, thereby
confirming the close relationship and indicating that C. thermophilum is a later synonym
of S. thermodepolymerans.info:eu-repo/semantics/publishedVersio
Consistent deformations of [p,p]-type gauge field theories
Using BRST-cohomological techniques, we analyze the consistent deformations
of theories describing free tensor gauge fields whose symmetries are
represented by Young tableaux made of two columns of equal length p, p>1. Under
the assumptions of locality and Poincare invariance, we find that there is no
consistent deformation of these theories that non-trivially modifies the gauge
algebra and/or the gauge transformations. Adding the requirement that the
deformation contains no more than two derivatives, the only possible
deformation is a cosmological-constant-like term.Comment: 17 pages, details of a proof added, accepted for publication in JHE
On gravitational interactions for massive higher spins in
In this paper we investigate gravitational interactions of massive higher
spin fields in three dimensional space with arbitrary value of
cosmological constant including flat Minkowski space. We use frame-like gauge
description for such massive fields adopted to three-dimensional case. At
first, we carefully analyze the procedure of switching on gravitational
interactions in the linear approximation on the example of massive spin-3 field
and then proceed with the generalization to the case of arbitrary integer spin
field. As a result we construct a cubic interaction vertex linear in spin-2
field and quadratic in higher spin field on background. As in the
massless case the vertex does not contain any higher derivative corrections to
the Lagrangian and/or gauge transformations. Thus, even after switching on
gravitational interactions, one can freely consider any massless or partially
massless limits as well as the flat one.Comment: 21 pages. Some clarifications and 1 new reference added. Version to
appear in the J.Phys.A special volume on "Higher Spin Theories and AdS/CFT"
edited by Matthias Gaberdiel and Mikhail Vasilie
Master Higher-Spin Particle
We propose a "master" higher-spin (HS) particle system. The particle model
relevant to the unfolded formulation of HS theory, as well as the HS particle
model with a bosonic counterpart of supersymmetry, follow from the master model
as its two different gauges. Quantization of the master system gives rise to a
new form of the massless HS equations in an extended space involving, besides
extra spinorial coordinates, also a complex scalar one. As solutions to these
equations we recover the massless HS multiplet with fields of all integer and
half-integer helicities, and obtain new multiplets with a non-zero minimal
helicity. The HS multiplets are described by complex wave functions which are
holomorphic in the scalar coordinate and carry an extra U(1) charge q. The
latter fully characterizes the given multiplet by fixing the minimal helicity
as q/2. We construct a twistorial formulation of the master system and present
the general solution of the associate HS equations through an unconstrained
twistor "prepotential".Comment: 21 pages, minor corrections, version to appear in Class. Quantum Gra
A note on spin-s duality
Duality is investigated for higher spin (), free, massless, bosonic
gauge fields. We show how the dual formulations can be derived from a common
"parent", first-order action. This goes beyond most of the previous treatments
where higher-spin duality was investigated at the level of the equations of
motion only. In D=4 spacetime dimensions, the dual theories turn out to be
described by the same Pauli-Fierz (s=2) or Fronsdal () action (as it
is the case for spin 1). In the particular s=2 D=5 case, the Pauli-Fierz action
and the Curtright action are shown to be related through duality. A crucial
ingredient of the analysis is given by the first-order, gauge-like,
reformulation of higher spin theories due to Vasiliev.Comment: Minor corrections, reference adde
Supersymmetric Higher Spin Theories
We revisit the higher spin extensions of the anti de Sitter algebra in four
dimensions that incorporate internal symmetries and admit representations that
contain fermions, classified long ago by Konstein and Vasiliev. We construct
the , Euclidean and Kleinian version of these algebras, as well as the
corresponding fully nonlinear Vasiliev type higher spin theories, in which the
reality conditions we impose on the master fields play a crucial role. The
supersymmetric higher spin theory in , on which we elaborate
further, is included in this class of models. A subset of Konstein-Vasiliev
algebras are the higher spin extensions of the superalgebras
for mod 4 and can be realized using
fermionic oscillators. We tensor the higher superalgebras of the latter kind
with appropriate internal symmetry groups and show that the mod 4
higher spin algebras are isomorphic to those with mod 4. We
describe the fully nonlinear higher spin theories based on these algebras as
well, and we elaborate further on the supersymmetric theory,
providing two equivalent descriptions one of which exhibits manifestly its
relation to the supersymmetric higher spin theory.Comment: 30 pages. Contribution to J. Phys. A special volume on "Higher Spin
Theories and AdS/CFT" edited by M. R. Gaberdiel and M. Vasilie
Propagating modes of non-Abelian tensor gauge field of second rank
In the recently proposed extension of the YM theory, non-Abelian tensor gauge
field of the second rank is represented by a general tensor whose symmetric
part describes the propagation of charged gauge boson of helicity two and its
antisymmetric part - the helicity zero charged gauge boson. On the
non-interacting level these polarizations are similar to the polarizations of
the graviton and of the Abelian antisymmetric B field, but the interaction of
these gauge bosons carrying non-commutative internal charges cannot be directly
identified with the interaction of gravitons or B field. Our intention here is
to illustrate this result from different perspectives which would include
Bianchi identity for the corresponding field strength tensor and the analysis
of the second-order partial differential equation which describes in this
theory the propagation of non-Abelian tensor gauge field of the second rank.Comment: 22 pages, Latex fil
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