相关论文: On the proximity of black hole horizons: lessons f…

Black holes are often characterized by event horizons, following the literature that laid the mathematical foundations of the subject in the 1970s. However black hole event horizons have two fundamental conceptual limitations. First, they…

We investigate the geometrical structure of Vaidya's spacetime in the case of a white hole with decreasing mass, stabilising to a black hole in finite or infinite time or evaporating completely. Our approach relies on a detailed analysis of…

The Event Horizon Telescope's 2024 observations report a shift in the position angle of the brightness asymmetry in M87*, revealing time variability in the black hole's image. In this analysis, we investigate the time-dependent of a Vaidya…

We discuss the validity of the Thakurta metric to describe cosmological black holes by analysing the nature of its horizon. By adopting the preferred foliation of the Thakurta spacetime associated with the Kodama time, we demonstrate that…

The relation between event horizons and trapping horizons is investigated in a number of different situations with emphasis on their role in thermodynamics. A notion of constant change is introduced that in certain situations allows the…

We consider how the mass of the black hole decreases by the Hawking radiation in the Vaidya spacetime, using the concept of dynamical horizon equation, proposed by Ashtekar and Krishnan. Using the formula for the change of the dynamical…

I review elements of the foundations of black-hole theory with attention to problematic issues, and describe some techniques which either seem to help with the difficulties or at least investigate their scope. The definition of black holes…

The mass of a black hole can dynamically evolve due to various physical processes, such as for instance accretion, Hawking radiation, absorption of gravitational/electromagnetic waves, superradiance, etc. This evolution can have an impact…

The impressive images from the Event Horizon Telescope sharpen the conflict between our observations of gravitational phenomena and the principles of quantum mechanics. Two related scenarios for reconciling quantum mechanics with the…

Black and white holes play remarkably contrasting roles in general relativity versus observational astrophysics. While there is overwhelming observational evidence for the existence of compact objects that are "cold, dark, and heavy", which…

We present an alternative scheme of finding apparent horizons based on spectral methods applied to Robinson-Trautman spacetimes. We have considered distinct initial data such as representing the spheroids of matter and the head-on collision…

It is generally admitted that gravitational interactions become large at an invariant distance of order $1$ from the black hole horizon. We show that due to the ``atmosphere'' of high angular particles near the horizon strong gravitational…

For distant observers black holes are trapped spacetime domains bounded by apparent horizons. We review properties of the near-horizon geometry emphasizing the consequences of two common implicit assumptions of semiclassical physics. The…

The findings discussed in "Apparent Horizons of the Thakurta Spacetime and the Description of Cosmological Black Holes" deviate from prior research, particularly our study in Phys. Rev. D 95, 084031 (2017). We clarify this inconsistency,…

We have investigated the local invariant scalar observables - energy density and flux - which explicitly depend on the kinematics of the concerned observers in the Vaidya gravitational collapse geometry. The use of globally defined null…

We study the intriguing analogy between gravitational dynamics of the horizon and thermodynamics for the case of nonstationary radiating spherically symmetric black holes both in four dimensions and higher dimensions. By defining all…

We explore the possibility that spacetime horizons in 4D general relativity can be treated as manifestations of higher dimensions that induce fields on our 4D spacetime. In this paper we discuss the black hole event horizon, as an example…

Horizons of black holes or cosmologies are peculiar loci of spacetime where interesting physical effects takes place, some of which are probed by recent (EHT and LIGO) and future experiments (ET and LISA). We discuss that there are boundary…

We introduce the concept of a geometric horizon, which is a surface distinguished by the vanishing of certain curvature invariants which characterize its special algebraic character. We motivate its use for the detection of the event…

Working in a semi-classical setting, we consider solutions of the Einstein equations that exhibit light trapping in finite time according to distant observers. In spherical symmetry, we construct near-horizon quantities from the assumption…