919 research outputs found
Kerr metric, static observers and Fermi coordinates
The coordinate transformation which maps the Kerr metric written in standard
Boyer-Lindquist coordinates to its corresponding form adapted to the natural
local coordinates of an observer at rest at a fixed position in the equatorial
plane, i.e., Fermi coordinates for the neighborhood of a static observer world
line, is derived and discussed in a way which extends to any uniformly
circularly orbiting observer there.Comment: 15 page latex iopart class documen
Wedging spacetime principal null directions
Taking wedge products of the distinct principal null directions
associated with the eigen-bivectors of the Weyl tensor associated with the
Petrov classification, when linearly independent, one is able to express them
in terms of the eigenvalues governing this decomposition. We study here
algebraic and differential properties of such -forms by completing previous
geometrical results concerning type I spacetimes and extending that analysis to
algebraically special spacetimes with at least 2 distinct principal null
directions. A number of vacuum and nonvacuum spacetimes are examined to
illustrate the general treatment.Comment: 24 pages, no figure
Radiative Corrections to Longitudinal and Transverse Gauge Boson and Higgs Production
Radiative corrections to gauge boson and Higgs production computed recently
using soft-collinear effective theory (SCET) require the one-loop high-scale
matching coefficients in the standard model. We give explicit expressions for
the matching coefficients for the effective field theory (EFT) operators for q
qbar -> VV and q qbar -> phi^+ phi for a general gauge theory with an arbitrary
number of gauge groups. The group theory factors are given explicitly for the
standard model, including both QCD and electroweak corrections.Comment: 16 pages, 49 figure
Circular holonomy in the Taub-NUT spacetime
Parallel transport around closed circular orbits in the equatorial plane of
the Taub-NUT spacetime is analyzed to reveal the effect of the gravitomagnetic
monopole parameter on circular holonomy transformations. Investigating the
boost/rotation decomposition of the connection 1-form matrix evaluated along
these orbits, one finds a situation that reflects the behavior of the general
orthogonally transitive stationary axisymmetric case and indeed along Killing
trajectories in general.Comment: 9 pages, LaTeX iopart class, no figure
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