23 citations · 83 across the 9 of their papers we have counts for
9 papers
STOchastic LAttice Simulation of hybrid inflation
Tomoaki Murata, Yuichiro Tada
We investigate the spatial profile of the curvature perturbation generated in multi-waterfall hybrid inflation models, which are known to produce various topological defects. Using…
Ghost-free 2-form fields in cosmology: implications for gravitational parity violation
Yuki Horii, Tomoaki Murata, Tsutomu Kobayashi
We explore the possibility of parity-violating, nonminimally coupled 2-form field theories that retain the same dynamical degrees of freedom as a massive 2-form and thus are ghost-…
Stochastic-tail of the curvature perturbation in hybrid inflation
Tomoaki Murata, Yuichiro Tada
The exponential-tail behaviours of the probability density function (PDF) of the primordial curvature perturbation are confirmed in the mild-waterfall variants of hybrid inflation…
Chromo-natural inflation supported by enhanced friction from Horndeski gravity
Tomoaki Murata, Tsutomu Kobayashi
We study the extension of the chromo-natural inflation model by incorporating nonminimal coupling between the axion field and gravity. Nonminimal coupling is introduced so that it…
STOLAS: STOchastic LAttice Simulation of cosmic inflation
Yurino Mizuguchi, Tomoaki Murata, Yuichiro Tada
We develop a C++ package of the STOchastic LAttice Simulation (STOLAS) of cosmic inflation. It performs the numerical lattice simulation in the application of the stochastic- f…
Parity-violating scalar trispectrum from a rolling axion during inflation
Tomohiro Fujita, Tomoaki Murata, Ippei Obata +1
We study a mechanism of generating the trispectrum (4-point correlation) of curvature perturbation through the dynamics of a spectator axion field and U(1) gauge field during infla…
How does SU()-natural inflation isotropize the universe?
Tomoaki Murata, Tomohiro Fujita, Tsutomu Kobayashi
We study the homogeneous and anisotropic dynamics of pseudoscalar inflation coupled to an SU() gauge field. To see how the initially anisotropic universe is isotropized in such…
Dynamics of inflation with mutually orthogonal vector fields in a closed universe
Tomoaki Murata, Tsutomu Kobayashi
We study the dynamics of a homogeneous, isotropic, and positively curved universe in the presence of a SU(2) gauge field or a triplet of mutually orthogonal vector fields. In the S…
The isotropic attractor solution of axion-SU(2) inflation: Universal isotropization in Bianchi type-I geometry
Ira Wolfson, Azadeh Maleknejad, Tomoaki Murata +2
SU(2) gauge fields coupled to an axion field can acquire an isotropic background solution during inflation. We study homogeneous but anisotropic inflationary solutions in the prese…