collaborators

8 papers

gr-qc2026

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…

cond-mat.other2026

Operator dependence and robustness of spacetime-localized response in a quantum critical spin chain

Daichi Imagawa, Keiju Murata, Daisuke Yamamoto

We investigate the phenomenon of spacetime-localized response in a quantum critical spin system, with particular attention to how it depends on the spatial profile and operator con…

hep-th2026

Simulating Quantum Field Theories with Boundaries in Curved Spacetimes Using Open Spin Systems

Shunichiro Kinoshita, Keiju Murata, Daisuke Yamamoto +1

We develop a framework to simulate quantum field theories (QFTs) with boundaries in -dimenmsional curved spacetimes by employing open spin systems. Building upon our previou…

gr-qc2025

Singularity avoidance in black hole interiors by quantum gravity effects

Takeshi Chiba, Hiroki Matsui, Keiju Murata

The quantum nature of the Schwarzschild black hole interior is investigated through the Wheeler-DeWitt (WDW) equation. The interior of a static, spherically symmetric black hole is…

hep-th2025

Kaluza-Klein monopole with scalar multiplet hair

Takaaki Ishii, Keiju Murata, Keita Sugawara

We construct Kaluza-Klein monopole solutions with scalar hair provied by a massive complex scalar field multiplet that minimally couples to five-dimensional Einstein gravity. Writi…

hep-th2025

Spin systems as quantum simulators of quantum field theories in curved spacetimes

Shunichiro Kinoshita, Keiju Murata, Daisuke Yamamoto +1

We demonstrate that a quantum field theory (QFT) in general two-dimensional curved spacetimes can be realized by a system of quantum spins or qubits. We consider a spin-1/2 model o…