514 research outputs found
Cosmic Microwave Background-Weak Lensing Correlation: Analytical and Numerical Study of Nonlinearity and Implications for Dark Energy
Evolution of density fluctuations yields secondary anisotropies in the cosmic microwave background ( CMB), which are correlated with the same density fluctuations that can be measured by weak lensing (WL) surveys. We study the CMB-WL correlation induced by the integrated Sachs-Wolfe (ISW) effect and its nonlinear extension, the Rees-Sciama (RS) effect, using analytical models as well as N-body simulations. We show that an analytical model based on the time derivative of matter power spectrum agrees with simulations. All-sky cosmic-variance-limited CMB and WL surveys allow us to measure the correlation from the nonlinear RS effect with high significance (50 sigma) for l(max) = 10(4) whereas forthcoming missions such as Planck and LSST are expected to yield 4 l p 10 1.5 sigma detections, on the assumption of that the point-source contributions are negligible. We find that the CMB-WL correlation has a characteristic scale which is sensitive to the nature of dark energy.Alfred P. Sloan FellowshipAstronom
On the Systematic Errors of Cosmological-Scale Gravity Tests using Redshift Space Distortion: Non-linear Effects and the Halo Bias
Redshift space distortion (RSD) observed in galaxy redshift surveys is a
powerful tool to test gravity theories on cosmological scales, but the
systematic uncertainties must carefully be examined for future surveys with
large statistics. Here we employ various analytic models of RSD and estimate
the systematic errors on measurements of the structure growth-rate parameter,
, induced by non-linear effects and the halo bias with respect to
the dark matter distribution, by using halo catalogues from 40 realisations of
comoving Mpc cosmological N-body simulations. We
consider hypothetical redshift surveys at redshifts z=0.5, 1.35 and 2, and
different minimum halo mass thresholds in the range of --
. We find that the systematic error of
is greatly reduced to ~5 per cent level, when a recently proposed
analytical formula of RSD that takes into account the higher-order coupling
between the density and velocity fields is adopted, with a scale-dependent
parametric bias model. Dependence of the systematic error on the halo mass, the
redshift, and the maximum wavenumber used in the analysis is discussed. We also
find that the Wilson-Hilferty transformation is useful to improve the accuracy
of likelihood analysis when only a small number of modes are available in power
spectrum measurements.Comment: 10 pages, 8 figures, 1 table, accepted for publication in MNRA
Regardless-of-Speed Superconducting LSM Controlled-Repulsive MAGLEV Vehicle
This paper proposes a new repulsive Maglev vehicle which a superconducting linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. The combined levitation and propulsion control is carried out by controlling mechanical-load angle and armature-current. Dynamic simulations show successful operations with good ride-quality by using a compact control method proposed here
Gastroenteropancreatic neuroendocrine tumor of the accessory papilla of the duodenum: a case report
BackgroundContrary to the increasing incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs), GEP-NETs of the accessory papilla of the duodenum are extremely rare. Furthermore, there have been no recommendations regarding the treatment strategy for GEP-NETs of the accessory papilla of the duodenum. We present a case of GEP-NET of the accessory papilla of the duodenum successfully treated with robotic pancreatoduodenectomy.Case presentationA case of a 70-year-old complaining of no symptoms was diagnosed with GEP-NET of the accessory papilla of the duodenum. A 8-mm tumor was located at the submucosal layer with a biopsy demonstrating a neuroendocrine tumor grade 1. The patient underwent robotic pancreatoduodenectomy as curative resection for the tumor. The total operative time was 406 min with an estimated blood loss of 150 mL. The histological examination revealed a well-differentiated neuroendocrine tumor with low Ki-67 index (<1%). In the posterior areas of the pancreas, the lymph node metastases were detected. The patient was followed up for 6 months with no recurrence postoperatively.ConclusionsConsidering the potential risks of the lymph node metastases, the standard treatment strategy for GEP-NETs of the accessory papilla of the duodenum should be radical resection with pancreatoduodenectomy. Minimally invasive approach can be the alternative to the conventional open surgery
Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering
We perform an ensemble of -body simulations with particles for
101 flat CDM cosmological models sampled based on a maximin-distance Sliced
Latin Hypercube Design. By using the halo catalogs extracted at multiple
redshifts in the range of , we develop Dark Emulator, which enables
fast and accurate computations of the halo mass function, halo-matter
cross-correlation, and halo auto-correlation as a function of halo masses,
redshift, separations and cosmological models, based on the Principal Component
Analysis and the Gaussian Process Regression for the large-dimensional input
and output data vector. We assess the performance of the emulator using a
validation set of -body simulations that are not used in training the
emulator. We show that, for typical halos hosting CMASS galaxies in the Sloan
Digital Sky Survey, the emulator predicts the halo-matter cross correlation,
relevant for galaxy-galaxy weak lensing, with an accuracy better than and
the halo auto-correlation, relevant for galaxy clustering correlation, with an
accuracy better than . We give several demonstrations of the emulator. It
can be used to study properties of halo mass density profiles such as the
mass-concentration relation and splashback radius for different cosmologies.
The emulator outputs can be combined with an analytical prescription of
halo-galaxy connection such as the halo occupation distribution at the equation
level, instead of using the mock catalogs, to make accurate predictions of
galaxy clustering statistics such as the galaxy-galaxy weak lensing and the
projected correlation function for any model within the CDM cosmologies, in
a few CPU seconds.Comment: 46 pages, 47 figures; version accepted for publication in Ap
Pectoralis Major and Serratus Anterior Muscle Flap for Diaphragmatic Reconstruction
We have reported a new reconstruction method using a pectoralis major and serratus anterior muscle flap for diaphragmatic defects after chondrosarcoma resection. The reconstruction of diaphragmatic defects is challenging. In diaphragmatic reconstruction with chest wall defects, strong chest wall reconstruction and diaphragmatic flexibility are important to avoid interference with respiration. The artificial material Gore-Tex is used as the first choice, but it has infection-, exposure-, and durability-related drawbacks. As an alternative method using artificial material, we have reported our new technique—diaphragmatic reconstruction using a reversed-combined pectoralis major and serratus anterior muscle flap
Electron Beam Lithography for Large Area Patterning 2: Exposure Characteristics of Electrodeposited Thick Resist
Exposure characteristics of a large field deflection electron beam lithography system have been examined. Thick film mainly composed of unsaturated acrylic resins and prepared by electrodeposition process is proposed as a resist available to large area patterning. It is proved that the 20 μm thick resist is very sensitive to 60 kV electron beam and has the threshold dosage of 2.0 x 10-7 C/cm2. The spatial contours of equienergy density deposited by electron beam in a 20 μm thick resist on a semi-infinite thick copper substrate are calculated by Monte Carlo simulation for a line source with a lateral beam profile described by Gaussian distribution.
The comparison of Monte Carlo calculations with the experiment has led to conclusions that the line width of the electrodeposited resist is determined by the contour line corresponding to about 1.5 x 1019 eV/ cm3 and that line widths less than 100 μm can be obtained with high stability within a fluctuation of less than ±10% for the large scanning field of 52 mm x 52 mm
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