arXiv subjects

Seiken Chikazawa

Publications and source records attributed to Seiken Chikazawa.

2 recordsLinked to original sources

arXiv2026

New analytic solutions of non-SUSY black branes in $10$-D heterotic supergravity and the phase transition

In the exploration of the vast string landscape, we provide new analytic solutions of non-SUSY black branes in 10-D heterotic supergravity which exhibit a phase transition. Our black brane solutions carry two kinds of gauge charges but still are exact, which extends the recent developments in classification of heterotic branes. The solutions offer a novel method to embed previously known noncritical 2-D or 3-D solutions to the critical dimensions. Furthermore, by performing a perturbative analysis of the non-Abelian gauge field on this exact background, we analytically find that as the temperature decreases, a spontaneous symmetry breaking occurs, leading to a dynamical instability accompanied by gauge field condensation. This instability embodies a phase transition of black branes in heterotic supergravity, and analytically predicts the existence of unknown black hole solutions to be unveiled. Our results suggest that phase transition phenomena can be used to explore and analyze the phase structure of black hole solutions, for systematically discovering and classifying stringy black holes.

hep-th↗

arXiv2026

Rindler Physics with a UV Cutoff on the Lattice

We investigate quantum field theory in Rindler space with a UV cutoff by considering a free scalar field on a lattice in Rindler coordinates. We find that the Minkowski vacuum is not exactly thermal with respect to the local lattice Rindler Hamiltonian. Nevertheless, for observables sufficiently far from the horizon, the Wightman function and the Unruh--DeWitt detector response reproduce the expected thermal behavior in the continuum limit. Thus, the Unruh effect survives operationally, even though exact thermality is lost at the state level. We also show that the Rindler vacuum energy density reproduces the standard continuum behavior away from the horizon, while the UV singularity at the horizon is replaced by a stretched-horizon contribution. Furthermore, the retarded Green function exhibits a component reflected at the stretched horizon, implying that an ingoing wave packet is reflected at a proper distance of order the cutoff. This provides an effective brick-wall picture in the UV-regulated theory. Our analysis suggests that, once a cutoff is introduced, the global Minkowski description and the wedge description based on a local Rindler Hamiltonian are no longer equivalent at the operator level.

hep-th↗