Zhen Zhong

Sep 25, 2024 | mdpi.com | Zhen Zhong |Ningmu Zou |Xuping Zhang

1. IntroductionFiber sensors integrated with optical grating, which are quasi-distributed, have played a great role in fields of seismic wave exploration [1], fiber-optic hydrophone [2], etc. However, the demodulation of fiber sensors integrated with optical grating is complicated and expensive. Recently, a distributed acoustic sensor (DAS) based on the principle of quantitative measurement of Φ-OTDR has been used to measure seismic waves and other vibration events [3,4].

Oct 24, 2023 | link.aps.org | Zhen Zhong |Departamento de Física |Instituto Técnico |Universidade de Lisboa

Recently, the piercing of a mini boson star by a black hole was studied, with tidal capture and the discovery of a “gravitational atom” being reported [Cardoso et al., Phys. Rev. D 106, 044030 (2022).]. Building on this research, we extend the study by including a hexic solitonic potential and explore the piercing of a solitonic boson star by a black hole. Notably, the solitonic boson star can reach higher compactness, which one might expect could alter the dynamics in this context.

Feb 15, 2023 | link.aps.org | Zhen Zhong |Departamento de Física |Instituto Técnico |Universidade de Lisboa

Abstract Motivated by recent results reporting the instability of horizonless objects with stable light rings, we revisit the linearized stability of such structures. In particular, we consider an exterior Kerr spacetime truncated at a surface where Dirichlet conditions on a massless scalar are imposed. This spacetime has ergoregions and light rings when the surface is placed sufficiently deep in the gravitational potential.