374 research outputs found
Growth, Foreign Direct Investment and the Environment: Evidence from Chinese Cities
In this paper we investigate the relationship between economic growth and industrial pollution emissions in China using data for 112 major cities between 2001 and 2004. Using disaggregated data we separate FDI inflows from Hong Kong, Macao and Taiwan from those of other foreign economies. We examine four industrial water pollution indicators (wastewater, chemical oxygen demand, hexavalent chromium compounds, and petroleum-like matter) and four industrial air pollution indicators (waste gas, sulphur dioxide, soot and dust). Our results suggest that most air and water emissions rise with increases in economic growth at current income levels. The share of total output produced by firms from Hong Kong, Macao and Taiwan has a positive effect on emissions although this effect is only significant for three industrial water pollution emissions. The share of total output produced by firms from other foreign economies can be beneficial, detrimental or neutral, depending on the pollutants considered. --FDI,economic growth,pollution,cities
Growth, Foreign Direct Investment and the Environment: Evidence from Chinese Cities
In this paper we investigate the relationship between economic growth and industrial pollution emissions in China using data for 112 major cities between 2001 and 2004. Using disaggregated data we separate FDI inflows from Hong Kong, Macao and Taiwan from those of other foreign economies. We examine four industrial water pollution indicators (wastewater, chemical oxygen demand, hexavalent chromium compounds, and petroleum-like matter) and four industrial air pollution indicators (waste gas, sulphur dioxide, soot and dust). Our results suggest that most air and water emissions rise with increases in economic growth at current income levels. The share of total output produced by firms from Hong Kong, Macao and Taiwan has a positive effect on emissions although this effect is only significant for three industrial water pollution emissions. The share of total output produced by firms from other foreign economies can be beneficial, detrimental or neutral, depending on the pollutants considered
The Footprint of F-theory at the LHC
Recent work has shown that compactifications of F-theory provide a
potentially attractive phenomenological scenario. The low energy
characteristics of F-theory GUTs consist of a deformation away from a minimal
gauge mediation scenario with a high messenger scale. The soft scalar masses of
the theory are all shifted by a stringy effect which survives to low energies.
This effect can range from 0 GeV up to ~ 500 GeV. In this paper we study
potential collider signatures of F-theory GUTs, focussing in particular on ways
to distinguish this class of models from other theories with an MSSM spectrum.
To accomplish this, we have adapted the general footprint method developed
recently for distinguishing broad classes of string vacua to the specific case
of F-theory GUTs. We show that with only 5 fb^(-1) of simulated LHC data, it is
possible to distinguish many mSUGRA models and low messenger scale gauge
mediation models from F-theory GUTs. Moreover, we find that at 5 fb^(-1), the
stringy deformation away from minimal gauge mediation produces observable
consequences which can also be detected to a level of order ~ +/- 80 GeV. In
this way, it is possible to distinguish between models with a large and small
stringy deformation. At 50 fb^(-1), this improves to ~ +/- 10 GeV.Comment: 85 pages, 37 figure
Scaling Laws and Transient Times in 3He Induced Nuclear Fission
Fission excitation functions of compound nuclei in a mass region where shell
effects are expected to be very strong are shown to scale exactly according to
the transition state prediction once these shell effects are accounted for. The
fact that no deviations from the transition state method have been observed
within the experimentally investigated excitation energy regime allows one to
assign an upper limit for the transient time of 10 zs.Comment: 7 pages, TeX type, psfig, submitted to Phys. Rev. C, also available
at http://csa5.lbl.gov/moretto/ps/he3_paper.p
Density pertubation of unparticle dark matter in the flat Universe
The unparticle has been suggested as a candidate of dark matter. We
investigated the growth rate of the density perturbation for the unparticle
dark matter in the flat Universe. First, we consider the model in which
unparticle is the sole dark matter and find that the growth factor can be
approximated well by , where is
the equation of state of unparticle. Our results show that the presence of
modifies the behavior of the growth factor . For the second model
where unparticle co-exists with cold dark matter, the growth factor has a new
approximation and
is a function of . Thus the growth factor of unparticle is quite
different from that of usual dark matter. These information can help us know
more about unparticle and the early evolution of the Universe.Comment: 6pages, 4 figures, accepted for publication in Eur. Phys. J.
Basis Functions for Linear-Scaling First-Principles Calculations
In the framework of a recently reported linear-scaling method for
density-functional-pseudopotential calculations, we investigate the use of
localized basis functions for such work. We propose a basis set in which each
local orbital is represented in terms of an array of `blip functions'' on the
points of a grid. We analyze the relation between blip-function basis sets and
the plane-wave basis used in standard pseudopotential methods, derive criteria
for the approximate equivalence of the two, and describe practical tests of
these criteria. Techniques are presented for using blip-function basis sets in
linear-scaling calculations, and numerical tests of these techniques are
reported for Si crystal using both local and non-local pseudopotentials. We
find rapid convergence of the total energy to the values given by standard
plane-wave calculations as the radius of the linear-scaling localized orbitals
is increased.Comment: revtex file, with two encapsulated postscript figures, uses epsf.sty,
submitted to Phys. Rev.
Inflation, cold dark matter, and the central density problem
A problem with high central densities in dark halos has arisen in the context
of LCDM cosmologies with scale-invariant initial power spectra. Although n=1 is
often justified by appealing to the inflation scenario, inflationary models
with mild deviations from scale-invariance are not uncommon and models with
significant running of the spectral index are plausible. Even mild deviations
from scale-invariance can be important because halo collapse times and
densities depend on the relative amount of small-scale power. We choose several
popular models of inflation and work out the ramifications for galaxy central
densities. For each model, we calculate its COBE-normalized power spectrum and
deduce the implied halo densities using a semi-analytic method calibrated
against N-body simulations. We compare our predictions to a sample of dark
matter-dominated galaxies using a non-parametric measure of the density. While
standard n=1, LCDM halos are overdense by a factor of 6, several of our example
inflation+CDM models predict halo densities well within the range preferred by
observations. We also show how the presence of massive (0.5 eV) neutrinos may
help to alleviate the central density problem even with n=1. We conclude that
galaxy central densities may not be as problematic for the CDM paradigm as is
sometimes assumed: rather than telling us something about the nature of the
dark matter, galaxy rotation curves may be telling us something about inflation
and/or neutrinos. An important test of this idea will be an eventual consensus
on the value of sigma_8, the rms overdensity on the scale 8 h^-1 Mpc. Our
successful models have values of sigma_8 approximately 0.75, which is within
the range of recent determinations. Finally, models with n>1 (or sigma_8 > 1)
are highly disfavored.Comment: 13 pages, 6 figures. Minor changes made to reflect referee's
Comments, error in Eq. (18) corrected, references updated and corrected,
conclusions unchanged. Version accepted for publication in Phys. Rev. D,
scheduled for 15 August 200
Constraining the Power Spectrum using Clusters
(Shortened Abstract). We analyze a redshift sample of Abell/ACO clusters and
compare them with numerical simulations based on the truncated Zel'dovich
approximation (TZA), for a list of eleven dark matter (DM) models. For each
model we run several realizations, on which we estimate cosmic variance
effects. We analyse correlation statistics, the probability density function,
and supercluster properties from percolation analysis. As a general result, we
find that the distribution of galaxy clusters provides a constraint only on the
shape of the power spectrum, but not on its amplitude: a shape parameter 0.18 <
\Gamma < 0.25 and an effective spectral index at 20Mpc/h in the range
[-1.1,-0.9] are required by the Abell/ACO data. In order to obtain
complementary constraints on the spectrum amplitude, we consider the cluster
abundance as estimated using the Press--Schechter approach, whose reliability
is explicitly tested against N--body simulations. We conclude that, of the
cosmological models considered here, the only viable models are either Cold+Hot
DM ones with \Omega_\nu = [0.2-0.3], better if shared between two massive
neutrinos, and flat low-density CDM models with \Omega_0 = [0.3-0.5].Comment: 37 pages, Latex file, 9 figures; New Astronomy, in pres
Observation of Scaling Violations in Scaled Momentum Distributions at HERA
Charged particle production has been measured in deep inelastic scattering
(DIS) events over a large range of and using the ZEUS detector. The
evolution of the scaled momentum, , with in the range 10 to 1280
, has been investigated in the current fragmentation region of the Breit
frame. The results show clear evidence, in a single experiment, for scaling
violations in scaled momenta as a function of .Comment: 21 pages including 4 figures, to be published in Physics Letters B.
Two references adde
D* Production in Deep Inelastic Scattering at HERA
This paper presents measurements of D^{*\pm} production in deep inelastic
scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The
data have been taken with the ZEUS detector at HERA. The decay channel
(+ c.c.) has been used in the study. The
cross section for inclusive D^{*\pm} production with
and is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region
{ GeV and }. Differential cross
sections as functions of p_T(D^{*\pm}), and are
compared with next-to-leading order QCD calculations based on the photon-gluon
fusion production mechanism. After an extrapolation of the cross section to the
full kinematic region in p_T(D^{*\pm}) and (D^{*\pm}), the charm
contribution to the proton structure function is
determined for Bjorken between 2 10 and 5 10.Comment: 17 pages including 4 figure
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