71,456 research outputs found
New criteria to identify spectrum
In this paper we give some new criteria for identifying the components of a
probability measure, in its Lebesgue decomposition. This enables us to give new
criteria to identify spectral types of self-adjoint operators on Hilbert
spaces, especially those of interest.Comment: 10 page
Quenching of spectroscopic factors for proton removal in oxygen isotopes
We present microscopic coupled-cluster calculations of the spectroscopic
factors for proton removal from the closed-shell oxygen isotopes
O with the chiral nucleon-nucleon interaction at
next-to-next-to-next-to-leading order. We include coupling-to-continuum degrees
of freedom by using a Hartree-Fock basis built from a Woods-Saxon
single-particle basis. This basis treats bound and continuum states on an equal
footing. We find a significant quenching of spectroscopic factors in the
neutron-rich oxygen isotopes, pointing to enhanced many-body correlations
induced by strong coupling to the scattering continuum above the neutron
emission thresholds.Comment: 3 figure
Inverse Statistics for Stocks and Markets
In recent publications, the authors have considered inverse statistics of the
Dow Jones Industrial Averaged (DJIA) [1-3]. Specifically, we argued that the
natural candidate for such statistics is the investment horizons distribution.
This is the distribution of waiting times needed to achieve a predefined level
of return obtained from detrended historic asset prices. Such a distribution
typically goes through a maximum at a time coined the {\em optimal investment
horizon}, , which defines the most likely waiting time for
obtaining a given return . By considering equal positive and negative
levels of return, we reported in [2,3] on a quantitative gain/loss asymmetry
most pronounced for short horizons. In the present paper, this gain/loss
asymmetry is re-visited for 2/3 of the individual stocks presently in the DJIA.
We show that this gain/loss asymmetry established for the DJIA surprisingly is
{\em not} present in the time series of the individual stocks. The most
reasonable explanation for this fact is that the gain/loss asymmetry observed
in the DJIA as well as in the SP500 and Nasdaq are due to movements in the
market as a whole, {\it i.e.}, cooperative cascade processes (or
``synchronization'') which disappear in the inverse statistics of the
individual stocks.Comment: Revtex 13 pages, including 15 figure
Priorities for sustainable turfgrass management: a research and industry perspective
This paper provides a brief review and assessment of the key environmental, regulatory and technical issues facing the turfgrass sector with specific reference to the European context. It considers the range of externalities or ‘drivers for change' facing the industry, and the challenges and opportunities available for promoting and achieving more sustainable turfgrass management within the sports, landscape and amenity sectors. The analysis confirms that there are a number of key areas where a concerted research and industrial effort is required. These include responding to the pressures from government demands for greater environmental regulation, the increasing pressure on natural resources (notably water, energy and land), the emerging role of turf management in supporting ecosystem services and enhancing biodiversity, the continued need to promote integrated pest management, and the looming challenges posed by a changing climate, and urgent need to adapt. Whilst many of these externalities appear to be risks to the sports turf industry, there will also be significant opportunities, for those where the labour, energy and agronomic costs are minimized and where the drive to adopt a multifunctional approach to sportsturf management is embraced
Hyperon effects on the properties of -stable neutron star matter
We present results from Brueckner-Hartree-Fock calculations for
-stable neutron star matter with nucleonic and hyperonic degrees of
freedom employing the most recent parametrizations of the baryon-baryon
interaction of the Nijmegen group. Only and are present up
to densities . The corresponding equations of state are then used
to compute properties of neutron stars such as masses and radii.Comment: 4 pages, contributed talk at HYP2000, Torino, 23-27 Oct. 200
Large boron--epoxy filament-wound pressure vessels
Advanced composite material used to fabricate pressure vessel is prepeg (partially cured) consisting of continuous, parallel boron filaments in epoxy resin matrix arranged to form tape. To fabricate chamber, tape is wound on form which must be removable after composite has been cured. Configuration of boron--epoxy composite pressure vessel was determined by computer program
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