782 citations · 8.5k across the 161 of their papers we have counts for
13 papers · 1 filter
Potential reconstruction from general power spectrum in single-field inflation
Ki-Young Choi, Jinn-Ouk Gong, Su-beom Kang +1
We suggest a new method to reconstruct, within canonical single-field inflation, the inflaton potential directly from the primordial power spectrum which may deviate significantly…
Reconstruction of potentials of the hybrid inflation in the light of primordial black hole formation
Ki-Young Choi, Su-beom Kang, Rathul Nath Raveendran
The large enhancement of the primordial power spectrum of the curvature perturbation can seed the formation of primordial black hole, that can play as a dark matter component in th…
Constraining dark matter-neutrino interactions with IceCube-170922A
Ki-Young Choi, Jongkuk Kim, Carsten Rott
Astrophysical neutrinos travel long distances from their sources to the Earth traversing dark matter halos of clusters of galaxies and that of our own Milky Way. The interaction of…
A new bound on the low reheating temperature with dark matter
Ki-Young Choi, Tomo Takahashi
We investigate a new bound on the low reheating temperature in a scenario where the Universe experiences early matter-domination before reheating after which the standard big bang…
Primordial perturbations from dilaton-induced gauge fields
Kiwoon Choi, Ki-Young Choi, Hyungjin Kim +1
We study the primordial scalar and tensor perturbations in inflation scenario involving a spectator dilaton field. In our setup, the rolling spectator dilaton causes a tachyonic in…
WIMP isocurvature perturbation and small scale structure
Ki-Young Choi, Jinn-Ouk Gong, Chang Sub Shin
The adiabatic perturbation of dark matter is damped during the kinetic decoupling due to the collision with relativistic component on sub-horizon scales. However the isocurvature p…
Review of axino dark matter
Ki-Young Choi, Jihn E. Kim, Leszek Roszkowski
We review the status of axino dark matter. Two hierarchy problems, the strong CP problem and the gauge hierarchy problem, have led to introducing into particle physics a spontaneou…
Modulated reheating by curvaton
Ki-Young Choi, Osamu Seto
There might be a light scalar field during inflation which is not responsible for the accelerating inflationary expansion. Then, its quantum fluctuation is stretched during inflati…
Primordial curvature perturbation during and at the end of multi-field inflation
Ki-Young Choi, Soo A Kim, Bumseok Kyae
We study the generation of the primordial curvature perturbation in multi-field inflation. Considering both the evolution of the perturbation during inflation and the effects gener…
Natural Hybrid Inflation Model with Large Non-Gaussianity
Ki-Young Choi, Bumseok Kyae
We propose an inflationary model ("natural hybrid model"), which combines the supersymmetric hybrid model and the natural inflation model to achieve the spectral index of 0.96, and…
Non-Gaussianity and gravitational wave background in curvaton with a double well potential
Ki-Young Choi, Osamu Seto
We study the density perturbation by a curvaton with a double well potential and estimate the nonlinear parameters for non-Gaussianity and the amplitude of gravitational wave backg…
Review of local non-Gaussianity from multi-field inflation
Christian T. Byrnes, Ki-Young Choi
We review models which generate a large non-Gaussianity of the local form. We first briefly consider three models which generate the non-Gaussianity either at or after the end of i…
How the curvaton scenario, modulated reheating and an inhomogeneous end of inflation are related
Laila Alabidi, Karim A. Malik, Christian T. Byrnes +1
In this paper we analyse three models of the early universe, for which the respective mechanisms for generating the curvature perturbation are considered disparate. We find that in…