199 citations · 4.2k across the 135 of their papers we have counts for
15 papers · 1 filter
Lower bound of the tensor-to-scalar ratio in a nearly quadratic chaotic inflation model in supergravity
Keisuke Harigaya, Masahiro Kawasaki, Tsutomu T. Yanagida
We consider an initial condition problem in a nearly quadratic chaotic inflation model in supergravity. We introduce shift symmetry breaking not only in the superpotential but also…
Anomaly Mediated Gaugino Mass and Path-Integral Measure
Keisuke Harigaya, Masahiro Ibe
In recent years, there have been controversy concerning the anomaly mediated gaugino mass in the superspace formalism of supergravity. In this paper, we reexamine the gaugino mass…
CDM/baryon isocurvature perturbations in a sneutrino curvaton model
Keisuke Harigaya, Taku Hayakawa, Masahiro Kawasaki +1
Matter isocurvature perturbations are strictly constrained from cosmic microwave background observations. We study a sneutrino curvaton model where both cold dark matter (CDM)/bary…
R-symmetric Axion/Natural Inflation in Supergravity via Deformed Moduli Dynamics
Keisuke Harigaya, Masahiro Ibe, Tsutomu T. Yanagida
We construct a natural inflation model in supergravity where the inflaton is identified with a modulus field possessing a shift symmetry. The superpotential for the inflaton is gen…
Phase Locked Inflation -- Effectively Trans-Planckian Natural Inflation
Keisuke Harigaya, Masahiro Ibe
A model of natural inflation with an effectively trans-Planckian decay constant can be easily achieved by the "phase locking" mechanism while keeping field values in the effective…
Dynamical Fractional Chaotic Inflation -- Dynamical Generation of a Fractional Power-Law Potential for Chaotic Inflation
Keisuke Harigaya, Masahiro Ibe, Kai Schmitz +1
Chaotic inflation based on a simple monomial scalar potential, V(phi) ~ phi^p, is an attractive large-field model of inflation capable of generating a sizable tensor-to-scalar rati…
Pure Gravity Mediation and Chaotic Inflation in Supergravity
Keisuke Harigaya, Tsutomu T. Yanagida
We investigate compatibility of the pure gravity mediation (or the minimal split supersymmetry) with chaotic inflation models in supergravity. We find that an approximate Z2 parity…
Simple realization of inflaton potential on a Riemann surface
Keisuke Harigaya, Masahiro Ibe
The observation of the B-mode in the cosmic microwave background radiation combined with the so-called Lyth bound suggests the trans-Planckian variation of the inflaton field durin…
Affleck-Dine Baryogenesis and Dark Matter Production after High-scale Inflation
Keisuke Harigaya, Ayuki Kamada, Masahiro Kawasaki +2
The discovery of the primordial B-mode polarisation by the BICEP2 experiment indicates inflation with a relatively high energy scale. Taking this indication into account, we propos…
Dynamical Chaotic Inflation in the Light of BICEP2
Keisuke Harigaya, Masahiro Ibe, Kai Schmitz +1
The measurement of a large tensor-to-scalar ratio by the BICEP2 experiment, r = 0.20 (-0.05)(+0.07), severely restricts the landscape of viable inflationary models and shifts atten…
High-Scale SUSY Breaking Models in light of the BICEP2 Result
Keisuke Harigaya, Masahiro Ibe, Koji Ichikawa +2
The large value of the tensor-to-scalar ratio in the cosmic microwave background radiation reported by the BICEP2 collaboration gives strong impact on models of supersymmetry (SUSY…
Discovery of Large Scale Tensor Mode and Chaotic Inflation in Supergravity
Keisuke Harigaya, Tsutomu T. Yanagida
The BICEP2 collaboration has recently reported a large tensor fluctuation in the cosmic microwave background, which suggests chaotic inflation models. In this letter, we reconsider…
Gaugino coannihilations
Keisuke Harigaya, Kunio Kaneta, Shigeki Matsumoto
The high-scale supersymmetry (SUSY) breaking scenario is now attracting many attentions, because it is consistent with almost all experiments of particle physics, astrophysics, and…
Dark Matter Production in Late Time Reheating
Keisuke Harigaya, Masahiro Kawasaki, Kyohei Mukaida +1
We estimate dark matter density for the Universe with a reheating temperature smaller than the mass of dark matter, assuming dark matter to be a weakly interacting massive particle…
Baryon Asymmetry, Dark Matter, and Density Perturbation from PBH
Tomohiro Fujita, Keisuke Harigaya, Masahiro Kawasaki +1
We investigate the consistency of a scenario in which the baryon asymmetry, dark matters, as well as the cosmic density perturbation are generated simultaneously through the evapor…