activity
20242026
collaborators

6 papers

gr-qc2026

Trapped Surface as a Cosmic Censor

Hideo Furugori, Daisuke Yoshida, Kaho Yoshimura

We formulate a local geometric criterion for weak cosmic censorship in black hole overcharging and overspinning thought experiments. Under the null convergence and generic conditio…

gr-qc2026

Apparent Horizons Associated with Dynamical Black Hole Entropy

Hideo Furugori, Kanji Nishii, Daisuke Yoshida +1

We define entropic marginally outer trapped surfaces (E-MOTSs) as a generalization of apparent horizons. We then show that, under first-order perturbations around a stationary blac…

gr-qc2025

Consistency between Bulk and Boundary Causalities in Asymptotically Anti-de Sitter Spacetimes

Lei Fu, Keisuke Izumi, Daisuke Yoshida

We investigate the consistency between bulk and boundary causalities in static, spherically symmetric, asymptotically anti-de Sitter (AdS) spacetimes. We derive a general formula t…

gr-qc2025

The First Law and Weak Cosmic Censorship for de Sitter Black Holes

Daisuke Yoshida, Kaho Yoshimura

We apply Iyer-Wald's covariant phase space formalism to asymptotically de Sitter spacetimes and establish the thermodynamic first law, expressed in terms of the Abbott-Deser mass.…

gr-qc2025

Multi-Sheet Wormholes in the Gravitational Soliton Formalism

Yusuke Makita, Keisuke Izumi, Daisuke Yoshida +1

We analytically construct static regular solutions describing wormholes that connect multiple asymptotic regions, supported by a phantom scalar field. The solutions are static and…

gr-qc2024

Removing naked singularities in static axially symmetric spacetimes by patching with the flat spacetimes

Daiki Saito, Daisuke Yoshida

We investigate static, axially symmetric spacetimes without naked singularities that are constructed by patching Weyl class spacetimes with the flat spacetimes. Once the exterior g…