193 research outputs found

### A new constraints separation for the original D=10 massless superparticle

We study the problem of covariant separation between first and second class
constraints for the $D=10$ Brink-Schwarz superparticle. Opposite to the
supersymmetric light-cone frame separation, we show here that there is a
Lorentz covariant way to identify the second class constraints such that,
however, supersymmetry is broken. Consequences for the $D=10$ superstring are
briefly discussed.Comment: 13 page

### A new spin-2 self-dual model in $D=2+1$

There are three self-dual models of massive particles of helicity +2 (or -2)
in $D=2+1$. Each model is of first, second, and third-order in derivatives.
Here we derive a new self-dual model of fourth-order, \cL {SD}^{(4)}, which
follows from the third-order model (linearized topologically massive gravity)
via Noether embedment of the linearized Weyl symmetry. In fact, each self-dual
model can be obtained from the previous one \cL {SD}^{(i)} \to \cL
{SD}^{(i+1)}, i=1,2,3 by the Noether embedment of an appropriate gauge
symmetry, culminating in \cL {SD}^{(4)}. The new model may be identified with
the linearized version of \cL {HDTMG} = \epsilon^{\mu\nu\rho}
\Gamma_{\mu\gamma}^\epsilon (\p_\nu\Gamma_{\epsilon\rho}^\gamma +
(2/3)\Gamma_{\nu\delta}^\gamma \Gamma_{\rho\epsilon}^\delta) /8 m +
\sqrt{-g}(R_{\mu\nu} R^{\nu\mu} - 3 R^2/8) /2 m^2 . We also construct a master
action relating the third-order self-dual model to \cL {SD}^{(4)} by means of
a mixing term with no particle content which assures spectrum equivalence of
\cL {SD}^{(4)} to other lower-order self-dual models despite its pure higher
derivative nature and the absence of the Einstein-Hilbert action. The relevant
degrees of freedom of \cL {SD}^{(4)} are encoded in a rank-two tensor which
is symmetric, traceless and transverse due to trivial (non-dynamic) identities,
contrary to other spin-2 self-dual models. We also show that the Noether
embedment of the Fierz-Pauli theory leads to the new massive gravity of
Bergshoeff, Hohm and Townsend.Comment: 14 pages, no figures, typos fixed, reference (19) modifie

### A note on the nonuniqueness of the massive Fierz-Pauli theory and spectator fields

It is possible to show that there are three independent families of models
describing a massive spin-2 particle via a rank-2 tensor. One of them contains
the massive Fierz-Pauli model, the only case described by a symmetric tensor.
The three families have different local symmetries in the massless limit and
can not be interconnected by any local field redefinition. We show here
however, that they can be related with the help of a decoupled and non dynamic
(spectator) field. The spectator field may be either an antisymmetric tensor
$B_{\mu\nu}=-B_{\nu\mu}$, a vector $A_{\mu}$ or a scalar field $\varphi$,
corresponding to each of the three families. The addition of the extra field
allows us to formulate master actions which interpolate between the symmetric
Fierz-Pauli theory and the other models. We argue that massive gravity models
based on the Fierz-Pauli theory are not expected to be equivalent to possible
local self-interacting theories built up on the top of the two new families of
massive spin-2 models.
The approach used here may be useful to investigate dual (nonsymmetric)
formulations of higher spin particles.Comment: 9 pages, no figure

### Massive spin-2 particle from a rank-2 tensor

Here we obtain all possible second-order theories for a rank-2 tensor which
describe a massive spin-2 particle. We start with a general second-order
Lagrangian with ten real parameters. The absence of lower spin modes and the
existence of two local field redefinitions leads us to only one free parameter.
The solutions split into three one-parameter classes according to the local
symmetries of the massless limit. In the class which contains the usual massive
Fierz-Pauli theory, the subset of spin-1 massless symmetries is maximal. In
another class where the subset of spin-0 symmetries is maximal, the massless
theory is invariant under Weyl transformations and the mass term does not need
to fit in the form of the Fierz-Pauli mass term. In the remaining third class
neither the spin-1 nor the spin-0 symmetry is maximal and we have a new family
of spin-2 massive theories.Comment: 17 pages, no figure

### Generalized duality between local vector theories in $D=2+1$

The existence of an interpolating master action does not guarantee the same
spectrum for the interpolated dual theories. In the specific case of a
generalized self-dual (GSD) model defined as the addition of the Maxwell term
to the self-dual model in $D=2+1$, previous master actions have furnished a
dual gauge theory which is either nonlocal or contains a ghost mode. Here we
show that by reducing the Maxwell term to first order by means of an auxiliary
field we are able to define a master action which interpolates between the GSD
model and a couple of non-interacting Maxwell-Chern-Simons theories of opposite
helicities. The presence of an auxiliary field explains the doubling of fields
in the dual gauge theory. A generalized duality transformation is defined and
both models can be interpreted as self-dual models. Furthermore, it is shown
how to obtain the gauge invariant correlators of the non-interacting MCS
theories from the correlators of the self-dual field in the GSD model and
vice-versa. The derivation of the non-interacting MCS theories from the GSD
model, as presented here, works in the opposite direction of the soldering
approach.Comment: 11 pages, no figures, to appear in J. of High Energy Phy

### A note on linearized "New Massive Gravity" in arbitrary dimensions

By means of a triple master action we deduce here a linearized version of the
"New Massive Gravity" (NMG) in arbitrary dimensions. The theory contains a
4th-order and a 2nd-order term in derivatives. The 4th-order term is invariant
under a generalized Weyl symmetry. The action is formulated in terms of a
traceless $\eta^{\mu\nu}\Omega_{\mu\nu\rho}=0$ mixed symmetry tensor
$\Omega_{\mu\nu\rho}=-\Omega_{\mu\rho\nu}$ and corresponds to the massive
Fierz-Pauli action with the replacement
e_{\mu\nu}=\p^{\rho}\Omega_{\mu\nu\rho}. The linearized 3D and 4D NMG
theories are recovered via the invertible maps $\Omega_{\mu\nu\rho} =
\epsilon_{\nu\rho}^{\quad\beta}h_{\beta\mu}$ and $\Omega_{\mu\nu\rho} =
\epsilon_{\nu\rho}^{\quad \gamma\delta}T_{[\gamma\delta]\mu}$ respectively.
The properties $h_{\mu\nu}=h_{\nu\mu}$ and $T_{[[\gamma\delta]\mu]}=0$ follow
from the traceless restriction. The equations of motion of the linearized NMG
theory can be written as zero "curvature" conditions \p_{\nu}T_{\rho\mu} -
\p_{\rho}T_{\nu\mu}=0 in arbitrary dimensions.Comment: 15 pages, no figures, few typos fixed, one more referenc

### Dual descriptions of massive spin-3 particles in $D=2+1$ via Noether gauge embedment

We present here a relationship among massive self-dual models for spin-3
particles in $D=2+1$ via the Noether Gauge Embedment $(NGE)$ procedure.
Starting with a first order model (in derivatives) $S_{SD(1)}$ we have obtained
a sequence of four self-dual models $S_{SD(i)}$ where $i=1,2,3,4$. We
demonstrate that the $NGE$ procedure generate the correct action for the
auxiliary fields automatically. We obtain the whole action for the $4th$ order
self-dual model including all the needed auxiliary fields to get rid of the
ghosts of the theory.Comment: 16 pages, 1 tabl

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