1,288 research outputs found
Supersymmetry and the Geometry of Taub-NUT
The supersymmetric extension of Taub-NUT space admits 4 standard
supersymmetries plus several additional non-standard ones. The geometrical
origin of these symmetries is traced. The result has applications to fermion
modes in gravitational instantons as well as in long-range monopole dynamics.Comment: 9 pages, NIKHEF-H/94-2
Domain boundaries, Goldstone bosons and gravitational waves
The dynamical behaviour of domain boundaries between different realizations
of the vacuum of scalar fields with spontaneously broken phases is
investigated. They correspond to zero-modes of the Goldstone fields, moving
with the speed of light, and turn out to be accompanied by strongly oscillating
gravitational fields. In certain space-time topologies this leads to a
quantization condition for the symmetry breaking scale in terms of the Planck
mass.Comment: 6 page
Propagators and Path Integrals
Path-integral expressions for one-particle propagators in scalar and
fermionic field theories are derived, for arbitrary mass. This establishes a
direct connection between field theory and specific classical point-particle
models. The role of world-line reparametrization invariance of the classical
action and the implementation of the corresponding BRST-symmetry in the quantum
theory are discussed. The presence of classical world-line supersymmetry is
shown to lead to an unwanted doubling of states for massive spin-1/2 particles.
The origin of this phenomenon is traced to a `hidden' topological fermionic
excitation. A different formulation of the pseudo-classical mechanics using a
bosonic representation of \gam_5 is shown to remove these extra states at the
expense of losing manifest supersymmetry.Comment: 35 pages, latex, no figures, additional references; to be published
in Nucl. Phys.
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