706 research outputs found
Embracing complexity in international forest governance: a way forward; Policy Brief
This Policy Brief summarizes the findings of a comprehensive assessment of scientific information about international forest governance carried out by an Expert Panel of over 30 of the world's leading scientists working in the areas of environmental governance and international forest law. It aims to provide policy and decision makers with essential knowledge and building blocks required for a more effective and inclusive governance of the world's forest
Scattering Angles in Kerr Metrics
Scattering angles for probes in Kerr metrics are derived for scattering in the equatorial plane of the black hole. We use a method that naturally resums all orders in the spin of the Kerr black hole, thus facilitating comparisons with scattering-angle computations based on the Post-Minkowskian expansion from scattering amplitudes or worldline calculations. We extend these results to spinning black-hole probes up to and including second order in the probe spin and any order in the Post- Minkowskian expansion, for probe spins aligned with the Kerr spin. When truncating to third Post-Minkowskian order, our results agree with those obtained by amplitude and worldline methods
Scheduling Bidirectional Traffic on a Path
We study the fundamental problem of scheduling bidirectional traffic along a
path composed of multiple segments. The main feature of the problem is that
jobs traveling in the same direction can be scheduled in quick succession on a
segment, while jobs in opposing directions cannot cross a segment at the same
time. We show that this tradeoff makes the problem significantly harder than
the related flow shop problem, by proving that it is NP-hard even for identical
jobs. We complement this result with a PTAS for a single segment and
non-identical jobs. If we allow some pairs of jobs traveling in different
directions to cross a segment concurrently, the problem becomes APX-hard even
on a single segment and with identical jobs. We give polynomial algorithms for
the setting with restricted compatibilities between jobs on a single and any
constant number of segments, respectively
The vital aspects of human capital for health-care professionals in the communication process with clients during the value creation in the extramural health-care in the Netherlands
CP violation at a linear collider with transverse polarization
We show how transverse beam polarization at colliders can provide a
novel means to search for CP violation by observing the distribution of a
single final-state particle without measuring its spin. We suggest an azimuthal
asymmetry which singles out interference terms between standard model
contribution and new-physics scalar or tensor effective interactions in the
limit in which the electron mass is neglected. Such terms are inaccessible with
unpolarized or longitudinally polarized beams. The asymmetry is sensitive to CP
violation when the transverse polarizations of the electron and positron are in
opposite senses. The sensitivity of planned future linear colliders to
new-physics CP violation in is estimated in a
model-independent parametrization. It would be possible to put a bound of TeV on the new-physics scale at the 90% C.L. for
GeV and , with transverse polarizations of
80% and 60% for the electron and positron beams, respectively.Comment: 15 pages, latex, includes 5 figures. This version (v3) corresponds to
publication in Physical Review; extended version of v2 which corresponded to
LC note LC-TH-2003-099 with corrected figure caption
Abarcando la complejidad en la gobernanza forestal internacional: el camino a seguir; Nota de Política
Inclure la complexité dans la gouvernance internationale des forêts: la voia à suivre; Synthèse Politique
Pure spinor computation towards open string three-loop
Using the recent results in the pure spinor formulation, we lay out a
ground-work towards the full momentum space amplitudes of open superstrings at
three-loop. After briefly reviewing the one-loop amplitude, we directly work
out the two-loop and reproduce the result that was obtained by a symmetry
argument. For the three-loop, first we use the two-loop regulator as a warm-up
exercise. The result vanishes. We then employ the regulator that has been
recently proposed by Aisaka and Berkovits (AB). It is noted that the terms in
higher power in that render the two-loop
regulator disqualified for the three-loop do not contribute. This with a few
other indications suggests a possibility that the AB regulator might also lead
to a vanishing result. Nevertheless, we argue that it is possible to acquire
the three-loop amplitude, and present a result that we anticipate to be the
three-loop amplitude.Comment: 41 pages, latex, cosmetic change
CP violation at colliders
The prospects of experimental detection of violation at and
colliders are reviewed. After a general discussion on the
quantities which can measure violation and on the implications of the
theorem, various possibilities of measuring violation arising
outside the standard model are taken up. violation in leptonic processes,
especially polarization effects in are discussed
next. violation in and production and decay is
also described. (Based on talk presented at the WHEPP3, Madras, January 1994).Comment: 20 pages, latex, no figures (only revision is the comment that the
article is based on a talk presented at WHEPP3, Madras, January 1994
Large Electric Dipole Moments of Heavy Leptons
In many models of CP violation, the electric dipole moments (EDMs) of leptons
scale as the cube of the lepton mass. In these models, the EDM of a 100 GeV
heavy lepton would be a billion times greater than that of the muon, and could
be as large as a 0.01 e-fermi. In other models, in which the heavy leptons have
different properties from the lighter generations, a similarly large EDM can be
obtained. A large EDM could dominate the electromagnetic properties of heavy
leptons. The angular distribution and production cross-section of both charged
and neutral heavy leptons with large dipole moments is calculated and
discussed. The interesting possibility that a heavy neutrino with a large EDM
could leave an ionization track in a drift chamber is investigated.Comment: Discussion expanded extensively to include model-dependence of
results. Calculations unchanged. Note Added To Acknowledgments: This paper is
dedicated to the memory of Nathan Isgu
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