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Band-power reconstruction of the primordial fluctuation spectrum by the maximum likelihood reconstruction method
Ryo Nagata, Jun'ichi Yokoyama
The primordial curvature fluctuation spectrum is reconstructed by the maximum likelihood reconstruction method using the five-year Wilkinson Microwave Anisotropy Probe data of the…
Constraints on the time variation of the fine structure constant by the 5-year WMAP data
Masahiro Nakashima, Ryo Nagata, Jun'ichi Yokoyama
The constraints on the time variation of the fine structure constant at recombination epoch relative to its present value, $Δα/α\equiv (α_{\mathrm{rec}} - α_{\mathrm{now}})/α_{\mat…
Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis
Ryo Nagata, Jun'ichi Yokoyama
The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotrop…
Single-field inflation, anomalous enhancement of superhorizon fluctuations, and non-Gaussianity in primordial black hole formation
Ryo Saito, Jun'ichi Yokoyama, Ryo Nagata
We show a text-book potential for single-field inflation, namely, the Coleman-Weinberg model can induce double inflation and formation of primordial black holes (PBHs), because flu…
Observational Consequences of Evolution of Primordial Fluctuations in Scalar-Tensor Cosmology
Ryo Nagata, Takeshi Chiba, Naoshi Sugiyama
Evolution of primordial fluctuations in a Brans-Dicke type scalar-tensor gravity theory is comprehensively investigated. The harmonic attractor model, in which the scalar field has…