activity
20242026
collaborators

9 papers

astro-ph.CO2026

CMB Spectral Distortion Anisotropies from Acoustic Damping with primordial non-Gaussianity

Jens Chluba, Atsuhisa Ota, Nicola Bartolo

In this paper, we evaluate the precise distortion source and transfer functions caused by mixing of blackbodies of different temperatures using the recently developed frequency hie…

hep-ph2026

The Challenge of Detecting Quantum Nature of Gravitational Waves

Yu Miyauchi, Hidetoshi Omiya, Atsuhisa Ota +2

We investigate whether squeezing can provide an observable signature of quantum gravitational waves. Because a realistic detector couples only to a particular wave-packet mode, squ…

gr-qc2026

Ultraviolet Structure of Real-time Gravitational Wave Linear Response in a Resonant Scalar Field

Han Lai, Atsuhisa Ota

We study the real-time linear response of gravitational waves in a time-dependent resonant scalar field in a Minkowski background. In the Schwinger-Keldysh formalism, we develop an…

hep-th2026

Real-time Gravitational Wave Response in Thermal Spinning fields

Atsuhisa Ota, Hui-Yu Zhu, Yuhang Zhu

We study how the spin content of the thermal plasmas affects the propagation of gravitational waves in a radiation-dominated universe. As a simple but representative setup, we cons…

gr-qc2025

Symmetry principles of gravitational perturbations in thermal environments

Atsuhisa Ota

The thermal plasma induces a plasmon-like mass shift for gravitational perturbations, which can modify their dynamics near the horizon scale in the early radiation-dominated univer…

hep-th2025

Mode analysis of Nambu-Goldstone modes in U(1) charged first-order relativistic viscous hydrodynamics

Atsuhisa Ota

We conduct a mode analysis of a general -charged first-order relativistic hydrodynamics within the framework of effective field theory for dissipative fluids in flat Minkowsk…