8 citations · 15 across the 12 of their papers we have counts for
14 papers
Primordial Black Hole and Gravitational Wave by Peaked Cosmic Perturbations from Axion Curvaton
Keisuke Harigaya, Lian-Tao Wang, Jiangyi Yi
We demonstrate that an axion field can develop perturbations peaked at an intermediate wavenumber through its inflationary dynamics. We compute the resultant spectrum of gravitatio…
Cosmic Birefringence and Axiogenesis
Raymond T. Co, Lawrence J. Hall, Keisuke Harigaya +1
Recent analyses of Planck and ACT CMB data report a hint of isotropic cosmic birefringence (), corresponding to a parity-violating rotation of pol…
Kinetic Isocurvature Perturbation
Kyu Jung Bae, Dhong Yeon Cheong, Jinn-Ouk Gong +2
We formulate a new class of primordial perturbations called , where the mass density of dark matter is constant relative to the photon…
Spectator Composes a Gravitational Canon: Spectator-field-triggered Phase Transition During Inflation and its Anisotropic Gravitational Wave Signals
Yunjia Bao, Keisuke Harigaya
We propose a general framework in which a phase transition is triggered during cosmic inflation by the slow-roll dynamics of a spectator field. The topological defects formed at th…
Dark Matter and Baryon Asymmetry from Monopole-Axion Interactions
Raymond T. Co, Keisuke Harigaya, Isaac R. Wang +1
We introduce a novel mechanism where the kinetic energy of a rotating axion can be dissipated by the interactions with dark magnetic monopoles. This mechanism leads to a framework…
Bridging the divide: axion searches and axino phenomenology at colliders
Gabe Hoshino, Kristin Dona, Keisuke Harigaya +4
We discuss a phenomenological model that extends the minimal supersymmetric standard model to contain axions and their supersymmetric partner, the axino. In the supersymmetric DFSZ…
Enhanced Matter Power Spectrum from Axion Kination after Big Bang Nucleosynthesis
Raymond T. Co, Nicolas Fernandez, Akshay Ghalsasi +2
Despite stringent constraints from Big Bang Nucleosynthesis (BBN) and cosmic microwave background (CMB) observations, it is still possible for well-motivated particle physics model…
Lepton number violating signals of a parity symmetric model at TRISTAN
Keisuke Harigaya, Ryuichiro Kitano, Ryoto Takai
The parity solution to the strong CP problem necessarily extends the Standard Model to include the SU gauge sector and imposes restrictions on the structure of the Yuk…
Anisotropic Gravitational Waves from Anisotropic Axion Rotation
Arushi Bodas, Keisuke Harigaya, Keisuke Inomata +2
Gravitational waves (GWs) provide a powerful probe of the early universe due to their ability to free-stream across cosmic history. We study GW production in a compelling scenario…
Universal lower bound on the axion decay constant from free streaming effects
Keisuke Harigaya, Wayne Hu, Rayne Liu +1
We show that enhancement of the axion relic abundance compared to the standard misalignment contribution generically leads to the production of nonzero momentum axion modes, result…
Acoustic Misalignment Mechanism for Axion Dark Matter
Arushi Bodas, Raymond T. Co, Akshay Ghalsasi +2
A rotation in the field space of a complex scalar field corresponds to a Bose-Einstein condensation of charges. We point out that fluctuations in this rotating condensate ex…
Dynamical Solution to the Eta Problem in Spectator Field Models
Sana Elgamal, Keisuke Harigaya
We study a class of spectator field models that addresses the eta problem while providing a natural explanation for the observed slight deviation of the spectrum of curvature pertu…
Crescendo Beyond the Horizon: More Gravitational Waves from Domain Walls Bounded by Inflated Cosmic Strings
Yunjia Bao, Keisuke Harigaya, Lian-Tao Wang
Gravitational-wave (GW) signals offer a unique window into the dynamics of the early universe. GWs may be generated by the topological defects produced in the early universe, which…
Induced Gravitational Waves with Kination Era for Recent Pulsar Timing Array Signals
Keisuke Harigaya, Keisuke Inomata, Takahiro Terada
The evidence of the stochastic gravitational-wave background around the nano-hertz frequency range was recently found by worldwide pulsar timing array (PTA) collaborations. One of…