117 citations · 1k across the 40 of their papers we have counts for
40 papers
Anisotropic separate universe : Long-wavelength perturbations and conserved quantities
Daiki Saito, Atsushi Naruko
We investigate the long-wavelength evolution of linear perturbations in a homogeneous and anisotropic background with a scalar field coupled to a vector field. Using the spatial gr…
Evading Cosmological Strong Coupling in Non-minimally Coupled Vector Gravity
Antonio De Felice, Seishi Enomoto, Nagisa Hiroshima +1
Recent analyses of Proca theories with non-minimal curvature couplings have uncovered an additional scalar degree of freedom with an identically vanishing propagation speed, $c_s^2…
Imprints of flat space analyticity in de Sitter S-matrix
Jason Kristiano, Ryo Namba, Atsushi Naruko +2
The analytic structure of the flat-space S-matrix provides non-perturbative constraints on low-energy effective field theories based on the properties of high-energy theory. While…
Primordial black holes from a curvaton: the role of bimodal distributions
Tomotaka Kuroda, Atsushi Naruko, Vincent Vennin +1
We investigate the formation of primordial black holes in curvaton models of inflation, where the curvature perturbation is not only generated by the inflaton but also by a light s…
Evolution of a kink-antikink ensemble in a quantum vacuum
Mainak Mukhopadhyay, Kohta Murase, Atsushi Naruko +1
We study the flat spacetime dynamics of a classical field configuration corresponding to an ensemble of sine-Gordon kinks and antikinks, semi-classically coupled to a quantum…
Axion Cloud Decay due to the Axion-photon Conversion with Multi-pole Background Magnetic Fields
Yusuke Sakurai, Chul-Moon Yoo, Atsushi Naruko +1
We consider axion cloud decay due to the axion-photon conversion with multi-pole background magnetic fields. We focus on the and mode for the axion field configura…