379 research outputs found

    Lensing reconstruction from a patchwork of polarization maps

    Get PDF
    The lensing signals involved in CMB polarization maps have already been measured with ground-based experiments such as SPTpol and POLARBEAR, and would become important as a probe of cosmological and astrophysical issues in the near future. Sizes of polarization maps from ground-based experiments are, however, limited by contamination of long wavelength modes of observational noise. To further extract the lensing signals, we explore feasibility of measuring lensing signals from a collection of small sky maps each of which is observed separately by a ground-based large telescope, i.e., lensing reconstruction from a patchwork map of large sky coverage organized from small sky patches. We show that, although the B-mode power spectrum obtained from the patchwork map is biased due to baseline uncertainty, bias on the lensing potential would be negligible if the B-mode on scales larger than the blowup scale of 1/f1/f noise is removed in the lensing reconstruction. As examples of cosmological applications, we also show 1) the cross-correlations between the reconstructed lensing potential and full-sky temperature/polarization maps from satellite missions such as PLANCK and LiteBIRD, and 2) the use of the reconstructed potential for delensing B-mode polarization of LiteBIRD observation.Comment: 22 pages, 11 figures, replaced to match the published version in JCA

    Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis

    Full text link
    The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotropy. We apply the covariance matrix analysis and decompose the reconstructed spectrum into statistically independent band-powers. The statistically significant deviation from a simple power-law spectrum suggested by the analysis of the first-year data is not found in the five-year data except possibly at one point near the border of the wavenumber domain where accurate reconstruction is possible.Comment: 9page

    Fukanbi shisan shijo no kenkyu

    Get PDF
    制度:新 ; 文部省報告番号:乙1993号 ; 学位の種類:博士(経済学) ; 授与年月日:2005/11/15 ; 早大学位記番号:新411

    Beating the Standard Quantum Limit with Four Entangled Photons

    Full text link
    Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration and optical path length. Quantum entanglement enables higher precision than would otherwise be possible. We demonstrate an optical phase measurement with an entangled four photon interference visibility greater than the threshold to beat the standard quantum limit--the limit attainable without entanglement. These results open the way for new high-precision measurement applications.Comment: 5 pages, 4 figures Author name was slightly modifie

    Singlet Dirac Fermion Dark Matter with Mediators at Loop

    Full text link
    We study the phenomenology of singlet Dirac fermion dark matter in the simplified models where the dark matter interacts with the Standard Model particles at loop-level with the help of either colored or non-colored mediators. We especially focus on the implications of non-zero CP phases in the dark sector, which induce the electric dipole moments of the Dirac fermion dark matter as well as those of electron and nucleon. It is then found that the dark matter direct detection searches and the measurements of the electric dipole moments are able to test the singlet Dirac fermion dark matter scenario in the forthcoming experiments.Comment: 44 pages, 14 figures. Version accepted for publication in JHE
    corecore