105,220 research outputs found
Augmented Superfield Approach to Gauge-invariant Massive 2-Form Theory
We discuss the complete sets of the off-shell nilpotent (i.e. s^2_{(a)b} = 0)
and absolutely anticommuting (i.e. s_b s_{ab} + s_{ab} s_b = 0)
Becchi-Rouet-Stora-Tyutin (BRST) (s_b) and anti-BRST (s_{ab}) symmetries for
the (3+1)-dimensional (4D) gauge-invariant massive 2-form theory within the
framework of augmented superfield approach to BRST formalism. In this
formalism, we obtain the coupled (but equivalent) Lagrangian densities which
respect both BRST and anti-BRST symmetries on the constrained hypersurface
defined by the Curci-Ferrari type conditions. The absolute anticommutativity
property of the (anti-)BRST transformations (and corresponding generators) is
ensured by the existence of the Curci-Ferrari type conditions which emerge very
naturally in this formalism. Furthermore, the gauge-invariant restriction plays
a decisive role in deriving the proper (anti-)BRST transformations for the
St{\"u}ckelberg-like vector field.Comment: LaTeX file, 22 pages, no figures, version to appear in Eur. Phys. J.
C (2017
Gravitino Zero Modes on U(1)_R Strings
We consider theories with a spontaneously broken gauged R-symmetry, which can
only occur in supergravity models. These give rise to cosmic R-strings upon
which gravitino zero modes can exist. We construct solutions to the
Rarita-Schwinger spin-3/2 equation describing the gravitino in the field of
these cosmic strings and show that under some conditions these solutions may
give rise to gravitino currents on the string. We discuss further mathematical
and physical questions associated with these solutions.Comment: 18 pages, uses revte
Mixed and discontinuous finite volume element schemes for the optimal control of immiscible flow in porous media
We introduce a family of hybrid discretisations for the numerical
approximation of optimal control problems governed by the equations of
immiscible displacement in porous media. The proposed schemes are based on
mixed and discontinuous finite volume element methods in combination with the
optimise-then-discretise approach for the approximation of the optimal control
problem, leading to nonsymmetric algebraic systems, and employing minimum
regularity requirements. Estimates for the error (between a local reference
solution of the infinite dimensional optimal control problem and its hybrid
approximation) measured in suitable norms are derived, showing optimal orders
of convergence
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