From the 1 of 13 linked papers with an AI index.
13 papers
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…
Refocusing of Wheeler--DeWitt wave functions at inner horizons
Takeshi Chiba, Keiju Murata, Daiki Saito
We study quantum gravitational effects inside hyperbolic black holes with both outer and inner horizons by solving the Wheeler--DeWitt (WDW) equation in the minisuperspace approxim…
COSMOS: A numerical relativity code specialized for PBH formation
Chul-Moon Yoo, Hirotada Okawa, Albert Escrivà +7
Primordial black holes (PBHs) are black holes generated in the early universe without having gone through stellar evolution. In the standard formation process, PBHs are formed from…
Primordial black holes in excursion set theory: Formation probabilities, mass functions, and window functions
Hayami Iizuka, Daiki Saito, Koki Tokeshi
We study the mass function of primordial black holes (PBHs) within the excursion-set theory, in which the response of the stochastic density contrast to the variation of the coarse…
Rotating wormholes in five dimensions with equal angular momenta: large asymmetry regime
Keiya Uemichi, Yasutaka Koga, Daiki Saito +2
We clarify the relationship between rotation and the energy condition for stationary rotating wormhole solutions of the Einstein equations coupled to a phantom field in five-dimens…
Dynamical Formation of Self-Similar Wormholes
Yasutaka Koga, Ryota Maeda, Daiki Saito +1
We study spherically symmetric, self-similar wormhole solutions supported by colliding streams of negative-energy null dust, and their dynamical formation. Under the assumption of…