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Generalized G-Inflation —Inflation with the Most General Second-Order Field Equations—
We study generalized Galileons as a framework to develop the most general single-field inflation models ever, Generalized G-inflation, containing yet further generalization of Ginf lation, as well asExpand
Inflation driven by the Galileon field.
It is shown that (almost) scale-invariant curvature fluctuations can be generated even in the exactly de Sitter background and that the tensor-to-scalar ratio can take a significantly larger value than in the standard inflation models, violating the standard consistency relation. Expand
Non-Gaussianity in the modulated reheating scenario
We investigate the non-Gaussianity of primordial curvature perturbations in the modulated reheating scenario where the primordial perturbation is generated due to the spatial fluctuation of the rateExpand
Kinetically driven quintessence
Abstract Recently, a novel class of models for inflation has been found in which theinflationary dynamics is driven solely by (non-canonical) kinetic terms ratherthan by potential terms. As an obviousExpand
Effective field theory approach to quasi-single field inflation and effects of heavy fields
A bstractWe apply the effective field theory approach to quasi-single field inflation, which contains an additional scalar field with Hubble scale mass other than inflaton. Based on theExpand
Evolution of Axionic Strings and Spectrum of Axions Radiated from Them
Cosmological evolution of axionic strings is investigated by numerically solving field equations of a complex scalar field in $3+1$ dimensions. It is shown that the global strings relax to theExpand
Improved estimation of radiated axions from cosmological axionic strings
Cosmological evolution of axionic string network is analyzed in terms of field-theoretic simulations in a box of 512^3 grids, which are the largest ever, using a new and more efficient identificationExpand
Cosmological perturbations in a healthy extension of Hořava gravity
In Hořava's theory of gravity, Lorentz symmetry is broken in exchange for renormalizability, but the original theory has been argued to be plagued with problems associated with a new scalar modeExpand
Long-term dynamics of cosmological axion strings
We present results of new field-theoretic simulation of cosmological axion strings, which are eight times longer than previous ones. We have upgraded our simulation of physical strings in HiramatsuExpand