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From the 2 of 5 linked papers with an AI index.

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5 papers

astro-ph.CO2026

Anisotropic separate universe : Long-wavelength perturbations and conserved quantities

Daiki Saito, Atsushi Naruko

The paper extends the separate‑universe approach to anisotropic cosmologies, deriving super‑horizon solutions for scalar, vector, and tensor perturbations and identifying conserved…

hep-th2026

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…

hep-th2026

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…

astro-ph.CO2025

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…

hep-th2025

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…