247 research outputs found

    Precise Estimation of Cosmological Parameters Using a More Accurate Likelihood Function

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    The estimation of cosmological parameters from a given data set requires a construction of a likelihood function which, in general, has a complicated functional form. We adopt a Gaussian copula and constructed a copula likelihood function for the convergence power spectrum from a weak lensing survey. We show that the parameter estimation based on the Gaussian likelihood erroneously introduces a systematic shift in the confidence region, in particular for a parameter of the dark energy equation of state w. Thus, the copula likelihood should be used in future cosmological observations.Comment: 5 pages, 3 figures. Maches version published by the Physical Review Letter

    Extremely anisotropic suppression of huge enhancement of electrical resistivity by magnetic field in α-R2S3 (R = Sm, Dy).

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    The electrical resistivity ρ and magnetization M of α-R 2S3 (R = Sm, Dy) single crystals have been measured in various magnetic fields lying in the ac-plane of an orthorhombic crystal structure. The measurements have been carried out by rotating the single crystals around the b-axis (being set parallel to a horizontal direction), corresponding to the longitudinal direction of needle-shaped single crystals, in vertical magnetic fields. The electrical resistivity under no magnetic field shows huge enhancement in a narrow temperature range around the successive magnetic transition temperatures, as reported previously. Such enhancement is suppressed rapidly by applying a magnetic field, which has been clearly seen as diminishing of the ρ(T) peak. The magnetic field along the easy magnetization axis; H easy, moves the ρ(T) peak toward higher temperature with diminishing it, while the magnetic field along the hard magnetization axis; H hard, moves it to lower temperature. The suppression effect is extremely anisotropic for the orientation of the magnetic field lying in the ac-plane. It has been concluded that H easy suppresses the ρ enhancement most strongly. The suppression effect under H easy is more than 200 times larger at least in some cases than that under H hard

    Characteristics and generation process of surface waves excited on a perfect conductor surface

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    This paper was published in OPTICS EXPRESS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: https://doi.org/10.1364/OE.18.017576 . Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.We investigate characteristics and generation process of surface waves excited on a structured perfect conductor surface in order to clarify the mechanism of resonant transmission in metal hole arrays made of the perfect conductor. By using a metal hole array of kagome lattice, we can separate two modes excited on the perfect conductor surface; a surface wave and an edge mode. Our calculation based on finite-difference time-domain method provides a generation process of the edge mode and the surface wave that is responsible for the resonant transmission in metal hole arrays. (C) 2010 Optical Society of AmericaArticleOPTICS EXPRESS. 18(16):17576-17583 (2010)journal articl

    Novel Magnetic Behavior in CDW Compound GdTe3

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    The Number Density of Old Passively-Evolving Galaxies at z=1 in the Subaru/XMM-Newton Deep Survey Field

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    We obtained the number counts and the rest-frame B-band luminosity function of the color-selected old passively-evolving galaxies (OPEGs) at z=1 with very high statistical accuracy using a large and homogeneous sample of about 4000 such objects with z' <25 detected in the area of 1.03 deg^2 in the Subaru/XMM-Newton Deep Survey (SXDS) field. Our selection criteria are defined on the i'-z' and R-z' color-magnitude plane so that OPEGs at z=0.9-1.1 with formation redshift z_f=2-10 are properly sampled. The limiting magnitude corresponds to the luminosity of galaxies with M_*+3 at z=0. We made a pilot redshift observations for 99 OPEG candidates with 19 < z' < 22 and found that at least 78% (73/93) of the entire sample, or 95% (73/77) of these whose redshifts were obtained are indeed lie between z=0.87 and 1.12 and the most of their spectra show the continuum break and strong Ca H and K lines, indicating that these objects are indeed dominated by the old stellar populations. We then compare our results with the luminosity functions of the color- or the morphologically-selected early type galaxies at z=0 taking the evolutionary factor into account and found that the number density of old passive galaxies with sim M_* magnitude at z~1 averaged over the SXDS area is 40-60% of the equivalently red galaxies and 60-85% of the morphologically-selected E/S0 galaxies at z=0 depending on their luminosity evolution. It is revealed that more than half, but not all, of the present-day early-type galaxies had already been formed into quiescent passive galaxies at z=1.Comment: 28 pages, accepted for publication in Astrophysical Journal. The full version of the paper including Fig.3 and Fig.4 (large size) in full resolution is put at http://optik2.mtk.nao.ac.jp/~yamada/astronomy/sxdsred.htm

    Oral health status: relationship to nutrient and food intake among 80‐year‐old Japanese adults

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    Objectives The aim of this cross‐sectional study was to investigate the relationship of oral health status defined on the basis of presence of posterior occluding pairs ( POP s) and adequacy of removable denture fit as determined by self‐report to nutrient and food intake among older Japanese. Methods The subjects were 353 Japanese aged 80 years in 2008 and were classified into four groups according to the number of POP s, defined as pairs of occluding natural, restored, or fixed prosthetic postcanine teeth (range: 0–8) and removable denture status. The groups were: (i) good dentition ( n  =   56; 8 POP s and no removable prosthesis), (ii) well‐fitting dentures ( n  =   158; <8 POP s with self‐reported good‐fitting dentures), (iii) ill‐fitting dentures ( n  =   70; <8 POP s with self‐reported ill‐fitting dentures), and (iv) compromised dentition ( n  =   69; <8 POP s and no removable prosthesis). Multivariable analysis of the differences in nutrient and food intake outcome variables which were collected via validated food frequency questionnaire among the four oral health status groups was conducted using general linear models. Results Intake of multiple nutrients was significantly ( P  <   0.05) lower in the group with ill‐fitting dentures or compromised dentition than in the good dentition group. Vegetable, fish, and shellfish consumption was significantly lower in the ill‐fitting dentures or compromised dentition groups. No significant differences were seen in dietary intake between the well‐fitting dentures and good dentition groups. Conclusions Dietary intake was poorer in those with self‐perceived ill‐fitting dentures or fewer POP s than among those having all POP s. Regular dental care to maintain intact dentition, as well as dental treatment to replace missing teeth and ensure adequate denture fit and function, may be important to the diet intake and subsequent nutritional status of older Japanese.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108691/1/cdoe12100.pd
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