4,820 research outputs found
Brane Rotating Symmetries and the Fivebrane Equations of Motion
We show that the fully covariant equations of motion for the M-theory
fivebrane can be interpreted as charge conservation equations. The associated
charges induce `shift'-symmetries of the scalar, spinor and gauge-fields of the
fivebrane, so allowing an interpretation of all these fields as Goldstone
fields. We also find that the fivebrane possesses a new symmetry that is part
of the GL(32) automorphism group of the eleven dimensional supersymmetry
algebra.Comment: 15 pages, late
T-Duality of Green-Schwarz Superstrings on AdS(d) x S(d) x M(10-2d)
We verify the self-duality of Green-Schwarz supercoset sigma models on AdS backgrounds (d=2,3,5) under combined bosonic and fermionic
T-dualities without gauge fixing kappa symmetry. We also prove this property
for superstrings on AdS (d=2,3) described by
supercoset sigma models with the isometries governed by the exceptional Lie
supergroups (d=2) and
(d=3), which requires an additional T-dualisation along one of the spheres.
Then, by taking into account the contribution of non-supercoset fermionic modes
(up to the second order), we provide evidence for the T-self-duality of the
complete type IIA and IIB Green-Schwarz superstring theory on AdS (d=2,3) backgrounds with Ramond-Ramond fluxes. Finally,
applying the Buscher-like rules to T-dualising supergravity fields, we prove
the T-self-duality of the whole class of the AdS
superbackgrounds with Ramond-Ramond fluxes in the context of supergravity.Comment: v2: 57 pages, 1 figure, typos fixed and clarifications added, version
to appear in JHE
Constructing the Cubic Interaction Vertex of Higher Spin Gauge Fields
We propose a method of construction of a cubic interaction in massless Higher
Spin gauge theory both in flat and in AdS space-times of arbitrary dimensions.
We consider a triplet formulation of the Higher Spin gauge theory and
generalize the Higher Spin symmetry algebra of the free model to the
corresponding algebra for the case of cubic interaction. The generators of this
new algebra carry indexes which label the three Higher Spin fields involved
into the cubic interaction. The method is based on the use of oscillator
formalism and on the Becchi-Rouet-Stora-Tyutin (BRST) technique. We derive
general conditions on the form of cubic interaction vertex and discuss the
ambiguities of the vertex which result from field redefinitions. This method
can in principle be applied for constructing the Higher Spin interaction vertex
at any order. Our results are a first step towards the construction of a
Lagrangian for interacting Higher Spin gauge fields that can be holographically
studied.Comment: Published Version; comments added in introduction; minor typos and
references correcte
Sulfur-Oxidizing Bacteria in Soap Lake (Washington State), a Meromictic, Haloalkaline Lake with an Unprecedented High Sulfide Content
Culture-dependent and -independent techniques were used to study the diversity of chemolithoautotrophic sulfur-oxidizing bacteria in Soap Lake (Washington State), a meromictic, haloalkaline lake containing an unprecedentedly high sulfide concentration in the anoxic monimolimnion. Both approaches revealed the dominance of bacteria belonging to the genus Thioalkalimicrobium, which are common inhabitants of soda lakes. A dense population of Thioalkalimicrobium (up to 107 cells/ml) was found at the chemocline, which is characterized by a steep oxygen-sulfide gradient. Twelve Thioalkalimicrobium strains exhibiting three different phenotypes were isolated in pure culture from various locations in Soap Lake. The isolates fell into two groups according to 16S rRNA gene sequence analysis. One of the groups was closely related to T. cyclicum, which was isolated from Mono Lake (California), a transiently meromictic, haloalkaline lake. The second group, consisting of four isolates, was phylogenetically and phenotypically distinct from known Thioalkalimicrobium species and unique to Soap Lake. It represented a new species, for which we suggest the name Thioalkalimicrobium microaerophilum sp. nov
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