806 research outputs found
Interactions of a massless tensor field with the mixed symmetry of the Riemann tensor. No-go results
Non-trivial, consistent interactions of a free, massless tensor field t_{\mu
\nu |\alpha \beta} 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 Poincar\'{e} 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 cosmological-like 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.Comment: for version 3: 45 pages, uses amssymb; shortened version, the three
appendices from version 2 can be found in hep-th/040209
Geometry and dynamics of higher-spin frame fields
We give a systematic account of unconstrained free bosonic higher-spin fields
on D-dimensional Minkowski and (Anti-)de Sitter spaces in the frame formalism.
The generalized spin connections are determined by solving a chain of
torsion-like constraints. Via a generalization of the vielbein postulate these
allow to determine higher-spin Christoffel symbols, whose relation to the de
Wit--Freedman connections is discussed. We prove that the generalized Einstein
equations, despite being of higher-derivative order, give rise to the AdS
Fronsdal equations in the compensator formulation. To this end we derive
Damour-Deser identities for arbitrary spin on AdS. Finally we discuss the
possibility of a geometrical and local action principle, which is manifestly
invariant under unconstrained higher-spin symmetries.Comment: 30 pages, uses youngtab.sty, v2: minor changes, references adde
Interactions between a massless tensor field with the mixed symmetry of the Riemann tensor and a massless vector field
Consistent couplings between a massless tensor field with the mixed symmetry
of the Riemann tensor and a massless vector field are analyzed in the framework
of Lagrangian BRST cohomology. Under the assumptions on smoothness, locality,
Lorentz covariance, and Poincare invariance of the deformations, combined with
the requirement that the interacting Lagrangian is at most second-order
derivative, it is proved that there are no consistent cross-interactions
between a single massless tensor field with the mixed symmetry of the Riemann
tensor and one massless vector field.Comment: LaTeX, 24 page
Consistent interactions of dual linearized gravity in D=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.Comment: 63 pages, accepted for publication in Eur. Phys. J.
Classification of non-Riemannian doubled-yet-gauged spacetime
Assuming covariant fields as the `fundamental' variables,
Double Field Theory can accommodate novel geometries where a Riemannian metric
cannot be defined, even locally. Here we present a complete classification of
such non-Riemannian spacetimes in terms of two non-negative integers,
, . Upon these backgrounds, strings become
chiral and anti-chiral over and directions respectively, while
particles and strings are frozen over the directions. In
particular, we identify as Riemannian manifolds, as
non-relativistic spacetime, as Gomis-Ooguri non-relativistic string,
as ultra-relativistic Carroll geometry, and as Siegel's
chiral string. Combined with a covariant Kaluza-Klein ansatz which we further
spell, leads to Newton-Cartan gravity. Alternative to the conventional
string compactifications on small manifolds, non-Riemannian spacetime such as
, may open a new scheme of the dimensional reduction from ten to
four.Comment: 1+41 pages; v2) Refs added; v3) Published version; v4) Sign error in
(2.51) correcte
Holography, Unfolding and Higher-Spin Theory
Holographic duality is argued to relate classes of models that have
equivalent unfolded formulation, hence exhibiting different space-time
visualizations for the same theory. This general phenomenon is illustrated by
the higher-spin gauge theory shown to be dual to the theory of 3d
conformal currents of all spins interacting with 3d conformal higher-spin
fields of Chern-Simons type. Generally, the resulting 3d boundary conformal
theory is nonlinear, providing an interacting version of the 3d boundary sigma
model conjectured by Klebanov and Polyakov to be dual to the HS theory
in the large limit. Being a gauge theory it escapes the conditions of the
theorem of Maldacena and Zhiboedov, which force a 3d boundary conformal theory
to be free. Two reductions of particular higher-spin gauge theories where
boundary higher-spin gauge fields decouple from the currents and which have
free boundary duals are identified. Higher-spin holographic duality is also
discussed for the cases of and duality between higher-spin
theories and nonrelativistic quantum mechanics. In the latter case it is shown
in particular that () geometry in the higher-spin setup is dual to
the (inverted) harmonic potential in the quantum-mechanical setup.Comment: 57 pages, V2: Acknowledgements, references, comments, clarifications
and new section on reductions of particular HS theories associated with free
boundary theories are added. Typos corrected, V3. Minor corrections:
clarification in section 9 is added and typos correcte
Higher Spin Scattering in Superstring Theory
We compute scattering amplitudes of leading Regge trajectory states in open
superstring theories. Highest spin states at mass level n with spin s=n+1 for
bosons and s=n+1/2 for fermions are generated by particularly simple vertex
operators. Hence, the cubic couplings of bosons and fermions on the leading
Regge trajectory are given for arbitrary n. The same can be achieved for higher
point amplitudes, and this article focuses on four point level with one heavy
maximum spin state and three massless states in any bose-fermi combination,
putting particular emphasis on manifest cyclic symmetry. Except for the four
fermion coupling, all our results remain valid in any D<10 dimensional
compactification scenario, so they might become relevant at LHC in case of an
experimentally accessible low string scale. But even if not directly
observable, superstring amplitudes provide important clues on higher spin
dynamics and their consistent interactions in field theory.Comment: 31 pages; v3: final version published in Nuclear Physics
On manifolds admitting the consistent Lagrangian formulation for higher spin fields
We study a possibility of Lagrangian formulation for free higher spin bosonic
totally symmetric tensor field on the background manifold characterizing by the
arbitrary metric, vector and third rank tensor fields in framework of BRST
approach. Assuming existence of massless and flat limits in the Lagrangian and
using the most general form of the operators of constraints we show that the
algebra generated by these operators will be closed only for constant curvature
space with no nontrivial coupling to the third rank tensor and the strength of
the vector fields. This result finally proves that the consistent Lagrangian
formulation at the conditions under consideration is possible only in constant
curvature Riemann space.Comment: 11 pages; v2: minor typos corrected, a reference adde
No cross-interactions among different tensor fields with the mixed symmetry (3,1) intermediated by a vector field
Under the hypotheses of analyticity in the coupling constant, locality,
Lorentz covariance, and Poincare invariance of the deformations, combined with
the preservation of the number of derivatives on each field, the consistent
interactions between a collection of free massless tensor gauge fields with the
mixed symmetry of a two-column Young diagram of the type (3,1) and one Abelian
vector field, respectively a -form gauge field, are addressed. The main
result is that a single mixed symmetry tensor field from the collection gets
coupled to the vector field/-form. Our final result resembles to the well
known fact from General Relativity according to which there is one graviton in
a given world.Comment: 19 page
Two-dimensional interactions between a BF-type theory and a collection of vector fields
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.Comment: LaTeX 2e, 31 page
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