68,552 research outputs found

    Abundances of lithium, sodium, and potassium in Vega

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    Vega's photospheric abundances of Li, Na, and K were determined by using considerably weak lines measured on the very high-S/N spectrum, while the non-LTE correction and the gravity-darkening correction were adequately taken into account. It was confirmed that these alkali elements are mildly underabundant ([Li/H] ~ -0.6, [Na/H] ~ -0.3, and [K/H] ~ -0.2) compared to the solar system values, as generally seen also in other metals. Since the tendency of Li being more deficient than Na and K is qualitatively similar to what is seen in typical interstellar cloud, the process of interstellar gas accretion may be related with the abundance anomaly of Vega, as suspected in the case of lambda Boo stars.Comment: Accepted for publication in MNRAS; 8 pages, 9 figure

    Inflatonic baryogenesis with large tensor mode

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    We consider the complex inflaton field with a CP asymmetric term for its potential. This CP asymmetric term produces the global charge of the inflaton after inflation. With the assignment of the baryon number to the inflaton, the baryon asymmetry of the universe is produced by inflaton's decay. In addition to this, the U(1)U(1) breaking term modulates the curvature of the inflaton radial direction depending on its phase, which affects the tensor to scalar ratio. In this paper, we have studied the relation between the baryon asymmetry and the tensor to scalar ratio, then verified that the future CMB observation could test this baryogenesis scenario with large tensor mode.Comment: 11 pages, 3 figure

    A formulation of domain wall fermions in the Schroedinger functional

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    We present a formulation of domain wall fermions in the Schroedinger functional by following the universality argument given by L\"uscher. To check whether the formulation works, we examine the lowest eigenmode of the free domain wall fermion operator. We confirm that the theory belongs to a correct universality class and that the eigenvector is localized near the boundaries of the fifth dimension. We also investigate the chiral symmetry breaking structure of the four dimentional effective operator. We observe that the bulk chiral symmetry breaking disappears for a large fifth dimensional size, while the breaking originated by the boundary effects persists and exponetially decays away from the time boundaries.Comment: 7 pages, 2 figures, talk presented at The XXVII International Symposium on Lattice Field Theory, July 26-31, 2009, Peking University, Beijing, Chin

    General Report of the Researches of Snowpack Properties, Snowmelt Runoff and Evapotranspiration in Japan

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    A method was developed for estimating the distribution of snow and the snow water equivalent in Japan by combining LANDSAT data with the degree day method. A snow runoff model was improved and applied to the Okutadami River basin. The Martinec Rango model from the U.S. was applied to Japanese river basins to verify its applicability. This model was then compared with the Japanese model. Analysis of microwave measurements obtained by a radiometer on a tower over dry snow in Hokkaido indicate a certain correlation between brightness temperature and snowpack properties. A correlation between brightness temperature and depth of dry snow in an inland plain area was revealed in NIMBUS SMMR data obtained from the U.S. Calculation of evaporation using airborne remote sensing data and a Priestley-Taylor type of equation shows that the differentiation of evaporation with vegetation type is not remarkable because of little evapotransportation in winter
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