Publications (25)
Mixed Non-Gaussianity from Axion-Gauge Field Dynamics
Tomohiro Fujita, Ryo Namba, Ippei Obata
Is the DBI scalar field as fragile as other $k$-essence fields?
Shinji Mukohyama, Ryo Namba, Yota Watanabe
Curvature Perturbations from a Massive Vector Curvaton
Ryo Namba
New Scalar Field Quartessence
Robert Brandenberger, Rodrigo R. Cuzinatto, Jürg Fröhlich +1
Scale-dependent gravitational waves from a rolling axion
Ryo Namba, Marco Peloso, Maresuke Shiraishi +2
Where does curvaton reside? Differences between bulk and brane frames
François Larrouturou, Shinji Mukohyama, Ryo Namba +1
Stability of the Early Universe in Bigravity Theory
Katsuki Aoki, Kei-ichi Maeda, Ryo Namba
Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis
Neil Barnaby, Ryo Namba, Marco Peloso
Inflationary magneto-(non)genesis, increasing kinetic couplings, and the strong coupling problem
Hossein Bazrafshan Moghaddam, Evan McDonough, Ryo Namba +1
Hamiltonian analysis of nonprojectable HoÅava-Lifshitz gravity with $U(1)$ symmetry
Shinji Mukohyama, Ryo Namba, Rio Saitou +1
Testing statistics of the CMB B-mode polarization toward unambiguously establishing quantum fluctuation of vacuum
Maresuke Shiraishi, Chiaki Hikage, Ryo Namba +2
Gauge-flation confronted with Planck
Ryo Namba, Emanuela Dimastrogiovanni, Marco Peloso
Vector disformal transformation of generalized Proca theory
Guillem Domènech, Shinji Mukohyama, Ryo Namba +1
Pre-reheating Magnetogenesis in the Kinetic Coupling Model
Tomohiro Fujita, Ryo Namba
Derivative-dependent metric transformation and physical degrees of freedom
Guillem Domènech, Shinji Mukohyama, Ryo Namba +3
Blue Tensor Spectrum from Particle Production during Inflation
Shinji Mukohyama, Ryo Namba, Marco Peloso +1
Phenomenology of a Pseudo-Scalar Inflaton: Naturally Large Nongaussianity
Neil Barnaby, Ryo Namba, Marco Peloso
Instabilities in Horndeski Yang-Mills inflation
Jose Beltran Jimenez, Lavinia Heisenberg, Ryotaro Kase +2
Hamiltonian structure of scalar-tensor theories beyond Horndeski
Chunshan Lin, Shinji Mukohyama, Ryo Namba +1
Cosmology in rotation-invariant massive gravity with non-trivial fiducial metric
David Langlois, Shinji Mukohyama, Ryo Namba +1
Does the detection of primordial gravitational waves exclude low energy inflation?
Tomohiro Fujita, Ryo Namba, Yuichiro Tada
Stable solutions of inflation driven by vector fields
Razieh Emami, Shinji Mukohyama, Ryo Namba +1
Gravity waves and non-Gaussian features from particle production in a sector gravitationally coupled to the inflaton
Neil Barnaby, Jordan Moxon, Ryo Namba +3
Solving the flatness problem with an anisotropic instanton in HoÅava-Lifshitz gravity
Sebastian F. Bramberger, Andrew Coates, João Magueijo +3
Consistent generation of magnetic fields in axion inflation models
Tomohiro Fujita, Ryo Namba, Yuichiro Tada +2