3 papers
gr-qc2025
Attractive gravity probe surface in Einstein-Maxwell system
Kangjae Lee, Keisuke Izumi, Tetsuya Shiromizu +2
We derive areal inequalities for five types of attractive gravity probe surfaces, which were proposed by us in order to characterize the strength of gravity in different ways inclu…
gr-qc2024
Loosely trapped surface for slowly rotating black hole
Keisuke Izumi, Tetsuya Shiromizu, Daisuke Yoshida +2
We construct the marginal loosely trapped surface (marginal LTS) for the Kerr spacetime with a small Kerr parameter perturbatively, where the LTS condition is saturated. An LTS is…
gr-qc2024
A generalization of photon sphere based on escape/capture cone
Masaya Amo, Keisuke Izumi, Hirotaka Yoshino +2
In asymptotically flat spacetimes, bearing the null geodesics reaching the future null infinity in mind, we propose new concepts, the "dark horizons" as generalizations of the phot…