3,632 research outputs found
Parent field theory and unfolding in BRST first-quantized terms
For free-field theories associated with BRST first-quantized gauge systems,
we identify generalized auxiliary fields and pure gauge variables already at
the first-quantized level as the fields associated with algebraically
contractible pairs for the BRST operator. Locality of the field theory is taken
into account by separating the space--time degrees of freedom from the internal
ones. A standard extension of the first-quantized system, originally developed
to study quantization on curved manifolds, is used here for the construction of
a first-order parent field theory that has a remarkable property: by
elimination of generalized auxiliary fields, it can be reduced both to the
field theory corresponding to the original system and to its unfolded
formulation. As an application, we consider the free higher-spin gauge theories
of Fronsdal.Comment: LaTeX, amsart++, 40 pages, references added, final version to appear
in Commun. Math. Phy
Parent formulation at the Lagrangian level
The recently proposed first-order parent formalism at the level of equations
of motion is specialized to the case of Lagrangian systems. It is shown that
for diffeomorphism-invariant theories the parent formulation takes the form of
an AKSZ-type sigma model. The proposed formulation can be also seen as a
Lagrangian version of the BV-BRST extension of the Vasiliev unfolded approach.
We also discuss its possible interpretation as a multidimensional
generalization of the Hamiltonian BFV--BRST formalism. The general construction
is illustrated by examples of (parametrized) mechanics, relativistic particle,
Yang--Mills theory, and gravity.Comment: 26 pages, discussion of the truncation extended, typos corrected,
references adde
A minimal BV action for Vasiliev's four-dimensional higher spin gravity
The action principle for Vasiliev's four-dimensional higher-spin gravity
proposed recently by two of the authors, is converted into a minimal BV master
action using the AKSZ procedure, which amounts to replacing the classical
differential forms by vectorial superfields of fixed total degree given by the
sum of form degree and ghost number. The nilpotency of the BRST operator is
achieved by imposing boundary conditions and choosing appropriate gauge
transitions between charts leading to a globally-defined formulation based on a
principal bundle.Comment: 39 pages, 1 figure. Additional comments in the conclusion
Dynamical lattice instability versus spin liquid state in a frustrated spin chain system
The low-dimensional s=1/2 compound (NO)[Cu(NO3)3] has recently been suggested
to follow the Nersesyan-Tsvelik model of coupled spin chains. Such a system
shows unbound spinon excitations and a resonating valence bond ground state due
spin frustration. Our Raman scattering study demonstrates phonon anomalies as
well as the suppression of a broad magnetic scattering continuum for
temperatures below a characteristic temperature, T<T*=100K. We interpret these
effects as evidence for a dynamical interplay of spin and lattice degrees of
freedom that might lead to a further transition into a dimerized or
structurally distorted phase at lower temperatures.Comment: 5 pages, 6 figure
Interacting Vector-Spinor and Nilpotent Supersymmetry
We formulate an interacting theory of a vector-spinor field that gauges
anticommuting spinor charges \{Q_\alpha{}^I, Q_\beta{}^J \} = 0 in arbitrary
space-time dimensions. The field content of the system is (\psi_\mu{}^{\alpha
I}, \chi^{\alpha I J}, A_\mu{}^I), where \psi_\mu{}^{\alpha I} is a
vector-spinor in the adjoint representation of an arbitrary gauge group, and
A_\mu{}^I is its gauge field, while \chi^{\alpha I J} is an extra spinor with
antisymmetric adjoint indices I J. Amazingly, the consistency of the
vector-spinor field equation is maintained, despite its non-trivial
interactions.Comment: 10 pages, no figure
BTZ Black Hole as Solution of 3d Higher Spin Gauge Theory
BTZ black hole is interpreted as exact solution of 3d higher spin gauge
theory. Solutions for free massless fields in BTZ black hole background are
constructed with the help of the star-product algebra formalism underlying the
formulation of 3d higher spin theory. It is shown that a part of higher spin
symmetries remains unbroken for special values of the BTZ parameters.Comment: 31 pages, LaTeX; references correcte
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