9,888 research outputs found
CEO pay, shareholder returns, and accounting profits
We assess the impact on CEO pay (including salary, cash bonus, and benefits in kind) of changes in both accounting and shareholder returns in 99 British companies in the years 1972-89. After correcting for heterogeneity biases inherent in the standard specifications of the problem, we find a strong positive relationship between CEO pay and within-company changes in shareholder returns, and no statistically significant relationship between CEO pay and within-company changes in accounting returns. Differences between firms in long-term average profitability do appear to have a substantial effect on CEO pay, while differences between firms in shareholder returns add nothing to the within-firm pay dynamics.These findings call into question the rationale for explicitly share-based incentive schemes
Strong Lensing Analysis of A1689 from Deep Advanced Camera Images
We analyse deep multi-colour Advanced Camera images of the largest known
gravitational lens, A1689. Radial and tangential arcs delineate the critical
curves in unprecedented detail and many small counter-images are found near the
center of mass. We construct a flexible light deflection field to predict the
appearance and positions of counter-images. The model is refined as new
counter-images are identified and incorporated to improve the model, yielding a
total of 106 images of 30 multiply lensed background galaxies, spanning a wide
redshift range, 1.0z5.5. The resulting mass map is more circular in
projection than the clumpy distribution of cluster galaxies and the light is
more concentrated than the mass within . The projected mass profile
flattens steadily towards the center with a shallow mean slope of
, over the observed range,
r, matching well an NFW profile, but with a relatively high
concentration, . A softened isothermal profile
(\arcs) is not conclusively excluded, illustrating that
lensing constrains only projected quantities. Regarding cosmology, we clearly
detect the purely geometric increase of bend-angles with redshift. The
dependence on the cosmological parameters is weak due to the proximity of
A1689, , constraining the locus, .
This consistency with standard cosmology provides independent support for our
model, because the redshift information is not required to derive an accurate
mass map. Similarly, the relative fluxes of the multiple images are reproduced
well by our best fitting lens model.Comment: Accepted by ApJ. For high quality figures see
http://wise-obs.tau.ac.il/~kerens/A168
Equidistribution of zeros of holomorphic sections in the non compact setting
We consider N-tensor powers of a positive Hermitian line bundle L over a
non-compact complex manifold X. In the compact case, B. Shiffman and S.
Zelditch proved that the zeros of random sections become asymptotically
uniformly distributed with respect to the natural measure coming from the
curvature of L, as N tends to infinity. Under certain boundedness assumptions
on the curvature of the canonical line bundle of X and on the Chern form of L
we prove a non-compact version of this result. We give various applications,
including the limiting distribution of zeros of cusp forms with respect to the
principal congruence subgroups of SL2(Z) and to the hyperbolic measure, the
higher dimensional case of arithmetic quotients and the case of orthogonal
polynomials with weights at infinity. We also give estimates for the speed of
convergence of the currents of integration on the zero-divisors.Comment: 25 pages; v.2 is a final update to agree with the published pape
Uptake of gases in bundles of carbon nanotubes
Model calculations are presented which predict whether or not an arbitrary
gas experiences significant absorption within carbon nanotubes and/or bundles
of nanotubes. The potentials used in these calculations assume a conventional
form, based on a sum of two-body interactions with individual carbon atoms; the
latter employ energy and distance parameters which are derived from empirical
combining rules. The results confirm intuitive expectation that small atoms and
molecules are absorbed within both the interstitial channels and the tubes,
while large atoms and molecules are absorbed almost exclusively within the
tubes.Comment: 9 pages, 12 figures, submitted to PRB Newer version (8MAR2K). There
was an error in the old one (23JAN2K). Please download thi
Associations of vitamin D pathway genes with circulating 25-hydroxyvitamin-D, 1,25-dihydroxyvitamin-D, and prostate cancer:a nested case-control study
Vitamin D pathway single nucleotide polymorphisms (SNPs) are potentially useful proxies for investigating whether circulating vitamin D metabolites [total 25-hydroxyvitamin-D, 25(OH)D; 1,25-dihydroxyvitamin, 1,25(OH)2D] are causally related to prostate cancer. We investigated associations of sixteen SNPs across seven genes with prostate-specific antigen-detected prostate cancer
A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)
We present a measurement of time-dependent CP-violating asymmetries in
neutral B meson decays collected with the BABAR detector at the PEP-II
asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data
sample consists of 29.7 recorded at the
resonance and 3.9 off-resonance. One of the neutral B mesons,
which are produced in pairs at the , is fully reconstructed in
the CP decay modes , , , () and , or in flavor-eigenstate
modes involving and (). The flavor of the other neutral B meson is tagged at the time of
its decay, mainly with the charge of identified leptons and kaons. The proper
time elapsed between the decays is determined by measuring the distance between
the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample
finds . The value of the asymmetry amplitude is determined from
a simultaneous maximum-likelihood fit to the time-difference distribution of
the flavor-eigenstate sample and about 642 tagged decays in the
CP-eigenstate modes. We find , demonstrating that CP violation exists in the neutral B meson
system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review
Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions
The weak nucleon axial-vector form factor for quasi-elastic interactions is
determined using neutrino interaction data from the K2K Scintillating Fiber
detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of
which half are charged-current quasi-elastic interactions nu-mu n to mu- p
occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for
oxygen and assume the form factor is approximately a dipole with one parameter,
the axial vector mass M_A, and fit to the shape of the distribution of the
square of the momentum transfer from the nucleon to the nucleus. Our best fit
result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated
vector form factors from recent electron scattering experiments and a
discussion of the effects of the nucleon momentum on the shape of the fitted
distributions.Comment: 14 pages, 10 figures, 6 table
Measurement of the B+ --> p pbar K+ Branching Fraction and Study of the Decay Dynamics
With a sample of 232x10^6 Upsilon(4S) --> BBbar events collected with the
BaBar detector, we study the decay B+ --> p pbar K+ excluding charmonium decays
to ppbar. We measure a branching fraction Br(B+ --> p pbar
K+)=(6.7+/-0.5+/-0.4)x10^{-6}. An enhancement at low ppbar mass is observed and
the Dalitz plot asymmetry suggests dominance of the penguin amplitude in this B
decay. We search for a pentaquark candidate Theta*++ decaying into pK+ in the
mass range 1.43 to 2.00 GeV/c2 and set limits on Br(B+ -->
Theta*++pbar)xBr(Theta*++ --> pK+) at the 10^{-7} level.Comment: 8 pages, 7 postscript figures, submitted to Phys. Rev. D (Rapid
Communications
- âŠ