159 research outputs found
Power-law bounds on transfer matrices and quantum dynamics in one dimension II
We establish quantum dynamical lower bounds for a number of discrete
one-dimensional Schr\"odinger operators. These dynamical bounds are derived
from power-law upper bounds on the norms of transfer matrices. We develop
further the approach from part I and study many examples. Particular focus is
put on models with finitely or at most countably many exceptional energies for
which one can prove power-law bounds on transfer matrices. The models discussed
in this paper include substitution models, Sturmian models, a hierarchical
model, the prime model, and a class of moderately sparse potentials.Comment: 20 page
Optimizing future imaging survey of galaxies to confront dark energy and modified gravity models
We consider the extent to which future imaging surveys of galaxies can
distinguish between dark energy and modified gravity models for the origin of
the cosmic acceleration. Dynamical dark energy models may have similar
expansion rates as models of modified gravity, yet predict different growth of
structure histories. We parameterize the cosmic expansion by the two
parameters, and , and the linear growth rate of density fluctuations
by Linder's , independently. Dark energy models generically predict
, while the DGP model . To determine
if future imaging surveys can constrain within 20 percent (or
), we perform the Fisher matrix analysis for a weak lensing
survey such as the on-going Hyper Suprime-Cam (HSC) project. Under the
condition that the total observation time is fixed, we compute the Figure of
Merit (FoM) as a function of the exposure time \texp. We find that the
tomography technique effectively improves the FoM, which has a broad peak
around \texp\simeq {\rm several}\sim 10 minutes; a shallow and wide survey is
preferred to constrain the parameter. While
cannot be achieved by the HSC weak-lensing survey alone, one can improve the
constraints by combining with a follow-up spectroscopic survey like WFMOS
and/or future CMB observations.Comment: 18 pages, typos correcte
Predicting the Clustering of X-Ray Selected Galaxy Clusters in Flux-Limited Surveys
(abridged) We present a model to predict the clustering properties of X-ray
clusters in flux-limited surveys. Our technique correctly accounts for past
light-cone effects on the observed clustering and follows the non-linear
evolution in redshift of the underlying DM correlation function and cluster
bias factor. The conversion of the limiting flux of a survey into the
corresponding minimum mass of the hosting DM haloes is obtained by using
theoretical and empirical relations between mass, temperature and X-ray
luminosity of clusters. Finally, our model is calibrated to reproduce the
observed cluster counts adopting a temperature-luminosity relation moderately
evolving with redshift. We apply our technique to three existing catalogues:
BCS, XBACs and REFLEX samples. Moreover, we consider an example of possible
future space missions with fainter limiting flux. In general, we find that the
amplitude of the spatial correlation function is a decreasing function of the
limiting flux and that the EdS models always give smaller correlation
amplitudes than open or flat models with low matter density parameter. In the
case of XBACs, the comparison with previous estimates of the observational
spatial correlation shows that only the predictions of models with Omega_0m=0.3
are in good agreement with the data, while the EdS models have too low a
correlation strength. Finally, we use our technique to discuss the best
strategy for future surveys. Our results show that the choice of a wide area
catalogue, even with a brighter limiting flux, is preferable to a deeper, but
with smaller area, survey.Comment: 20 pages, Latex using MN style, 11 figures enclosed. Version accepted
for publication in MNRA
Extragalactic Science, Cosmology and Galactic Archaeology with the Subaru Prime Focus Spectrograph (PFS)
The Subaru Prime Focus Spectrograph (PFS) is a massively-multiplexed
fiber-fed optical and near-infrared 3-arm spectrograph (N_fiber=2400,
380<lambda<1260nm, 1.3 degree diameter FoV), offering unique opportunities in
survey astronomy. Here we summarize the science case feasible for a survey of
Subaru 300 nights. We describe plans to constrain the nature of dark energy via
a survey of emission line galaxies spanning a comoving volume of 9.3 (Gpc/h)^3
in the redshift range 0.8<z<2.4. In each of 6 redshift bins, the cosmological
distances will be measured to 3% precision via BAO, and redshift-space
distortions will be used to constrain structure growth to 6% precision. In the
GA program, radial velocities and chemical abundances of stars in the Milky Way
and M31 will be used to infer the past assembly histories of spiral galaxies
and the structure of their dark matter halos. Data will be secured for 10^6
stars in the Galactic thick-disk, halo and tidal streams as faint as V~22,
including stars with V < 20 to complement the goals of the Gaia mission. A
medium-resolution mode with R = 5000 to be implemented in the red arm will
allow the measurement of multiple alpha-element abundances and more precise
velocities for Galactic stars, elucidating the detailed chemo-dynamical
structure and evolution of each of the main stellar components of the Milky Way
Galaxy and of its dwarf spheroidal galaxies. For the extragalactic program, our
simulations suggest the wide avelength range will be powerful in probing the
galaxy population and its clustering over a wide redshift range. We propose to
conduct a color-selected survey of 1<z<2 galaxies and AGN over 16 deg^2 to
J~23.4, yielding a fair sample of galaxies with stellar masses above ~10^{10}Ms
at z~2. A two-tiered survey of higher redshift LBGs and LAEs will quantify the
properties of early systems close to the reionization epoch.Comment: This document describes the scientific program and requirements for
the Subaru Prime Focus Spectrograph (PFS) project. Made significant revision
based on studies for the Preliminary Design Review (PRD) held in Feb 2013.
The higher-resolution paper file is available from
http://member.ipmu.jp/masahiro.takada/pfs_astroph_rv.pd
Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System
We determine the stellar, planetary, and orbital properties of the transiting planetary system HD 209458 through a joint analysis of high-precision radial velocities, photometry, and timing of the secondary eclipse. Of primary interest is the strong detection of the Rossiter-McLaughlin effect, the alteration of photospheric line profiles that occurs because the planet occults part of the rotating surface of the star. We develop a new technique for modeling this effect and use it to determine the inclination of the planetary orbit relative to the apparent stellar equator (λ = -4Âș.4 ± 1Âș.4), and the line-of-sight rotation speed of the star (v sin /_â
= 4.70 ± 0.16 km s^(-1)). The uncertainty in these quantities has been reduced by an order of magnitude relative to the pioneering measurements by Queloz and collaborators. The small but nonzero misalignment is probably a relic of the planet formation epoch, because the expected timescale for tidal coplanarization is larger than the age of the star. Our determination of v sin /â
is a rare case in which rotational line broadening has been isolated from other broadening mechanisms
Large Scale Pressure Fluctuations and Sunyaev-Zel'dovich Effect
The Sunyaev-Zel'dovich (SZ) effect associated with pressure fluctuations of
the large scale structure gas distribution will be probed with current and
upcoming wide-field small angular scale cosmic microwave background
experiments. We study the generation of pressure fluctuations by baryons which
are present in virialized dark matter halos and by baryons present in small
overdensities. For collapsed halos, assuming the gas distribution is in
hydrostatic equilibrium with matter density distribution, we predict the
pressure power spectrum and bispectrum associated with the large scale
structure gas distribution by extending the dark matter halo approach which
describes the density field in terms of correlations between and within halos.
The projected pressure power spectrum allows a determination of the resulting
SZ power spectrum due to virialized structures. The unshocked photoionized
baryons present in smaller overdensities trace the Jeans-scale smoothed dark
matter distribution. They provide a lower limit to the SZ effect due to large
scale structure in the absence of massive collapsed halos. We extend our
calculations to discuss higher order statistics, such as bispectrum and
skewness in SZ data. The SZ-weak lensing cross-correlation is suggested as a
probe of correlations between dark matter and baryon density fields, while the
probability distribution functions of peak statistics of SZ halos in wide field
CMB data can be used as a probe of cosmology and non-Gaussian evolution of
large scale structure pressure fluctuations.Comment: 16 pages, 9 figures; Revised with expanded discussions. Phys. Rev. D.
(in press
Cosmological constraints from clustering properties of galaxy clusters
In this paper, we discuss improvements of the Suto et al. (2000) model, in
the light of recent theoretical developments (new theoretical mass functions, a
more accurate mass-temperature relation and an improved bias model) to predict
the clustering properties of galaxy clusters and to obtain constraints on
cosmological parameters. We re-derive the two-point correlation function of
clusters of galaxies for OCDM and LambdaCDM cosmological models, and we compare
these results with the observed spatial correlation function for clusters in
RASS1 (ROSAT All-Sky Survey 1), and in XBACs (X-RAY Brighest Abell-Type)
samples. The comparison shows that the best agreement is obtained for the
LambdaCDM model with Omega=0.3. The values of the correlation length obtained,
(r_\simeq 28.2 \pm 5.2 \rm h^{-1}} Mpc for LambdaCDM), are larger than those
found in the literature and comparable with the results found in Borgani,
Plionis & Kolokotronis (1999). (REST IN THE PAPER ABSTRACT)Comment: printed in A&
Observations and Theoretical Implications of the Large Separation Lensed Quasar SDSS J1004+4112
We study the recently discovered gravitational lens SDSS J1004+4112, the
first quasar lensed by a cluster of galaxies. It consists of four images with a
maximum separation of 14.62''. The system has been confirmed as a lensed quasar
at z=1.734 on the basis of deep imaging and spectroscopic follow-up
observations. We present color-magnitude relations for galaxies near the lens
plus spectroscopy of three central cluster members, which unambiguously confirm
that a cluster at z=0.68 is responsible for the large image separation. We find
a wide range of lens models consistent with the data, but they suggest four
general conclusions: (1) the brightest cluster galaxy and the center of the
cluster potential well appear to be offset by several kpc; (2) the cluster mass
distribution must be elongated in the North--South direction, which is
consistent with the observed distribution of cluster galaxies; (3) the
inference of a large tidal shear (~0.2) suggests significant substructure in
the cluster; and (4) enormous uncertainty in the predicted time delays between
the images means that measuring the delays would greatly improve constraints on
the models. We also compute the probability of such large separation lensing in
the SDSS quasar sample, on the basis of the CDM model. The lack of large
separation lenses in previous surveys and the discovery of one in SDSS together
imply a mass fluctuation normalization \sigma_8=1.0^{+0.4}_{-0.2} (95% CL), if
cluster dark matter halos have an inner slope -1.5. Shallower profiles would
require higher values of \sigma_8. Although the statistical conclusion might be
somewhat dependent on the degree of the complexity of the lens potential, the
discovery is consistent with the predictions of the abundance of cluster-scale
halos in the CDM scenario. (Abridged)Comment: 21 pages, 24 figures, 5 tables, accepted for publication in Ap
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