1,189 research outputs found
Chern-Simons Matter Theories and Higher Spin Gravity
We compute the parity violating three point amplitudes with one scalar leg in
higher spin gravity and compare results with those of Chern-Simons matter
theories. The three-point correlators of the free boson, free fermion, critical
vector model and Gross-Neveu model are reproduced including the dependence on
the Chern-Simons coupling. We also perform a simple test of the modified higher
spin equations proposed in arXiv:1605.02662 [hep-th] and find that the results
are consistent with the AdS/CFT correspondence.Comment: 39 pages; minor corrections and refs adde
Representations of p-brane topological charge algebras
The known extended algebras associated with p-branes are shown to be
generated as topological charge algebras of the standard p-brane actions. A
representation of the charges in terms of superspace forms is constructed. The
charges are shown to be the same in standard/extended superspace formulations
of the action.Comment: 22 pages. Typos fixed, refs added. Minor additions to comments
sectio
Scalar Field Corrections to AdS_4 Gravity from Higher Spin Gauge Theory
We compute the complete contribution to the stress-energy tensor in the
minimal bosonic higher spin theory in D=4 that is quadratic in the scalar
field. We find arbitrarily high derivative terms, and that the total sign of
the stress-energy tensor depends on the parity of the scalar field.Comment: 15 pages + appendix (30 pages
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
Test particles behavior in the framework of a lagrangian geometric theory with propagating torsion
Working in the lagrangian framework, we develop a geometric theory in vacuum
with propagating torsion; the antisymmetric and trace parts of the torsion
tensor, considered as derived from local potential fields, are taken and, using
the minimal action principle, their field equations are calculated. Actually
these will show themselves to be just equations for propagating waves giving
torsion a behavior similar to that of metric which, as known, propagates
through gravitational waves. Then we establish a principle of minimal
substitution to derive test particles equation of motion, obtaining, as result,
that they move along autoparallels. We then calculate the analogous of the
geodesic deviation for these trajectories and analyze their behavior in the
nonrelativistic limit, showing that the torsion trace potential has a
phenomenology which is indistinguishable from that of the gravitational
newtonian field; in this way we also give a reason for why there have never
been evidence for it.Comment: 12 pages, no figures, to appear on Int. Journ. Mod. Phys.
Hamiltonian analysis of Poincar\'e gauge theory scalar modes
The Hamiltonian constraint formalism is used to obtain the first explicit
complete analysis of non-trivial viable dynamic modes for the Poincar\'e gauge
theory of gravity. Two modes with propagating spin-zero torsion are analyzed.
The explicit form of the Hamiltonian is presented. All constraints are obtained
and classified. The Lagrange multipliers are derived. It is shown that a
massive spin- mode has normal dynamical propagation but the associated
massless is pure gauge. The spin- mode investigated here is also
viable in general. Both modes exhibit a simple type of ``constraint
bifurcation'' for certain special field/parameter values.Comment: 28 pages, LaTex, submitted to International Journal of Modern Physics
Current Exchanges and Unconstrained Higher Spins
The (Fang-)Fronsdal formulation for free fully symmetric (spinor-) tensors
rests on (gamma-)trace constraints on gauge fields and parameters. When these
are relaxed, glimpses of the underlying geometry emerge: the field equations
extend to non-local expressions involving the higher-spin curvatures, and with
only a pair of additional fields an equivalent ``minimal'' local formulation is
also possible. In this paper we complete the discussion of the ``minimal''
formulation for fully symmetric (spinor-) tensors, constructing one-parameter
families of Lagrangians and extending them to (A)dS backgrounds. We then turn
on external currents, that in this setting are subject to conventional
conservation laws and, by a close scrutiny of current exchanges in the various
formulations, we clarify the precise link between the local and non-local
versions of the theory. To this end, we first show the equivalence of the
constrained and unconstrained local formulations, and then identify a unique
set of non-local Lagrangian equations which behave in exactly the same fashion
in current exchanges.Comment: 37 pages, Latex. Typos corrected, note and references added. Final
version to appear in Nucl. Phys.
Witten-Nester Energy in Topologically Massive Gravity
We formulate topologically massive supergravity with cosmological constant in
the first order formalism, and construct the Noether supercurrent and
superpotential associated with its local supersymmetry. Using these results, we
construct in ordinary topologically massive gravity the Witten-Nester integral
for conserved charges containing spinors which satisfy a generalized version of
Witten equation on the initial value surface. We show that the Witten-Nester
charge, represented as an integral over the boundary of the initial value
surface produces the Abbott-Deser-Tekin energy for asymptotically anti de
Sitter spacetimes. We consider all values of the Chern-Simons coupling
constant, including the critical value known as the chiral point, and study the
cases of standard Brown-Henneaux boundary conditions, as well as their weaker
version that allow a slower fall-off. Studying the Witten-Nester energy as a
bulk integral over the initial value surface instead, we find a bound on the
energy, and through it the sufficient condition for the positivity of the
energy. In particular, we find that spacetimes of Petrov type N that admit
globally well defined solutions of the generalized Witten equation have
positive energy.Comment: 43 page
Massive higher spins and holography
We review recent progress towards the understanding of higher spin gauge
symmetry breaking in AdS space from a holographic vantage point. According to
the AdS/CFT correspondence, N=4 SYM theory at vanishing coupling constant
should be dual to a theory in AdS which exhibits higher spin gauge symmetry
enhancement. When the SYM coupling is non-zero, all but a handful of HS
currents are violated by anomalies, and correspondingly local higher spin
symmetry in the bulk gets spontaneously broken. In agreement with previous
results and holographic expectations, we find that, barring one notable
exception (spin 1 eating spin 0), the Goldstone modes responsible for HS
symmetry breaking in AdS have non-vanishing mass even in the limit in which the
gauge symmetry is restored. We show that spontaneous breaking a' la
Stueckelberg implies that the mass of the relevant spin s'=s-1 Goldstone field
is exactly the one predicted by the correspondence.Comment: 8 pages, talk presented by M.B. at the "Fourth Meeting on Constrained
Dynamics and Quantum gravity" held in Cala Gonone (Sardinia, Italy),
September 12-16, 200
On the covariant quantization of tensionless bosonic strings in AdS spacetime
The covariant quantization of the tensionless free bosonic (open and closed)
strings in AdS spaces is obtained. This is done by representing the AdS space
as an hyperboloid in a flat auxiliary space and by studying the resulting
string constrained hamiltonian system in the tensionless limit. It turns out
that the constraint algebra simplifies in the tensionless case in such a way
that the closed BRST quantization can be formulated and the theory admits then
an explicit covariant quantization scheme. This holds for any value of the
dimension of the AdS space.Comment: 1+16 pages; v4 two clarifications adde
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