4,153 research outputs found
String Amplitudes and Frame-like Formalism for Higher Spins
We analyze open string vertex operators describing connection gauge fields
for spin 3 in Vasiliev's frame-like formalism and perform their extended BRST
analysis. Gauge symmetry transformations, generalized zero torsion constraints
relating extra fields to the dynamical frame-like field and relation between
dynamical frame-like field and fully symmetric Fronsdal's field for spin 3 are
all realized in terms of BRST constraints on these vertex operators in string
theory. Using the construction, we analyze the 3-point correlator for spin 3
field and calculate Chern-Simons type cubic interactions described by
3-derivative Berends-Burgers-van Dam (BBD) type vertex in the frame-like
formalism.Comment: 25 page
Higher-spin current multiplets in operator-product expansions
Various formulas for currents with arbitrary spin are worked out in general
space-time dimension, in the free field limit and, at the bare level, in
presence of interactions. As the n-dimensional generalization of the
(conformal) vector field, the (n/2-1)-form is used. The two-point functions and
the higher-spin central charges are evaluated at one loop. As an application,
the higher-spin hierarchies generated by the stress-tensor operator-product
expansion are computed in supersymmetric theories. The results exhibit an
interesting universality.Comment: 19 pages. Introductory paragraph, misprint corrected and updated
references. CQG in pres
Higher Spin Conformal Currents in Minkowski Space
Using unfolded formulation of free equations for massless fields of all spins
we obtain explicit form of higher-spin conformal conserved charges bilinear in
4d massless fields of arbitrary spins.Comment: LaTeX, 10 pages. Corrected typo
A Higgs Mechanism for Gravity. Part II: Higher Spin Connections
We continue the work of hep-th/0503024 in which gravity is considered as the
Goldstone realization of a spontaneously broken diffeomorphism group. We
complete the discussion of the coset space Diff(d,R)/SO(1,d-1) formed by the
d-dimensional group of analytic diffeomorphisms and the Lorentz group. We find
that this coset space is parameterized by coordinates, a metric and an infinite
tower of higher-spin-like or generalized connections. We then study effective
actions for the corresponding symmetry breaking which gives mass to the higher
spin connections. Our model predicts that gravity is modified at high energies
by the exchange of massive higher spin particles.Comment: 17 pages; discussion on local Poincare invariance and matter currents
added; references adde
Holography of the N=1 Higher-Spin Theory on AdS4
We argue that the N=1 higher-spin theory on AdS4 is holographically dual to
the N=1 supersymmetric critical O(N) vector model in three dimensions. This
appears to be a special form of the AdS/CFT correspondence in which both
regular and irregular bulk modes have similar roles and their interplay leads
simultaneously to both the free and the interacting phases of the boundary
theory. We study various boundary conditions that correspond to boundary
deformations connecting, for large-N, the free and interacting boundary
theories. We point out the importance of parity in this holography and
elucidate the Higgs mechanism responsible for the breaking of higher-spin
symmetry for subleading N.Comment: 19 page
Spin-dependent conductivity of iron-based superconductors in a magnetic field
We report the results of a study of magnetic field features of electron
transport in heterojunctions with NS boundary inside iron-based
superconductors, represented by a binary phase of - FeSe and
oxyarsenide pnictide LaO(F)FeAs. We used the ability of self magnetic field of
the transport current to partially destroy superconductivity, no matter how low
the field may be, in the NS interface area, where, due to the proximity effect,
the superconducting order parameter, , disperses from 1 to 0 within the
scale of the Ginzburg-Landau coherence length. The following features of
transport were found:(i) at , magnetoresistance in systems with
different superconductors has different sign;(ii) sign and magnitude of the
magnetoresistance depend on the magnitude of current and temperature, and (iii)
in all operating modes where the contribution from Andreev reflection is
suppressed (),the hysteresis of the magnetoresistance
is present. Based on the results of the experiment and analysis it has been
concluded that there is along-range magnetic order in th eground normal state
of the iron-based superconductors studied, in the presence of itinerant
magnetism of conduction electrons which determines the possibility of
anisotropic spin-dependent exchange interaction with the local magnetic moments
of the ions.Comment: 9 pages, 7 figure
Higher Spin Fields in Siegel Space, Currents and Theta Functions
Dynamics of four-dimensional massless fields of all spins is formulated in
the Siegel space of complex symmetric matrices. It is shown that
the unfolded equations of free massless fields, that have a form of
multidimensional Schrodinger equations, naturally distinguish between positive-
and negative-frequency solutions of relativistic field equations, i.e.
particles and antiparticles. Multidimensional Riemann theta functions are shown
to solve massless field equations in the Siegel space. We establish the
correspondence between conserved higher-spin currents in four-dimensional
Minkowski space and those in the ten-dimensional matrix space. It is shown that
global symmetry parameters of the current in the matrix space should be
singular to reproduce a nonzero current in Minkowski space. The \D-function
integral evolution formulae for 4d massless fields in the Fock-Siegel space are
obtained. The generalization of the proposed scheme to higher dimensions and
systems of higher ranks is considered.Comment: LaTeX, 38 pages, v.3: clarifications, acknowledgements and references
added, typos corrected, v.4: more comments and references added, typos
corrected, the version to appear in JHE
Unfolded Scalar Supermultiplet
Unfolded equations of motion for N = 1, D = 4 scalar supermultiplet are
presented. We show how the superspace formulation emerges from the unfolded
formulation. To analyze supersymmetric unfolded equations we extend the
\sigma_-cohomology technics to the case with several operators \sigma_. The
role of higher \sigma_-cohomology in the derivation of constraints is
emphasized and illustrated by the example of scalar supermultiplet.Comment: 27 pages, no figures; minor corrections: clarifications added, typos
correcte
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
- …