Hoop conjecture and trapped surfaces in nonspherical massive systems

1991 ◽  
Vol 67 (8) ◽  
pp. 949-952 ◽  
Author(s):  
Edward Malec
Keyword(s):  
Trapped Surfaces ◽  
Hoop Conjecture

scholarly journals Formation of dynamically transversely trapping surfaces and the stretched hoop conjecture

2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Hirotaka Yoshino ◽  
Keisuke Izumi ◽  
Tetsuya Shiromizu ◽  
Yoshimune Tomikawa
Keyword(s):  
Black Holes ◽  
Initial Data ◽  
Apparent Horizon ◽  
Ring System ◽  
Conformally Flat ◽  
Trapped Surfaces ◽  
Marginally Trapped Surface ◽  
Spherical Topology ◽  
Hoop Conjecture ◽  
Trapped Surface

Abstract A dynamically transversely trapping surface (DTTS) is a new concept for an extension of a photon sphere that appropriately represents a strong gravity region and has close analogy with a trapped surface. We study formation of a marginally DTTS in time-symmetric, conformally flat initial data with two black holes, with a spindle-shaped source, and with a ring-shaped source, and clarify that $\mathcal{C}\lesssim 6\pi GM$ describes the condition for the DTTS formation well, where $\mathcal{C}$ is the circumference and $M$ is the mass of the system. This indicates that an understanding analogous to the hoop conjecture for the horizon formation is possible. Exploring the ring system further, we find configurations where a marginally DTTS with the torus topology forms inside a marginally DTTS with the spherical topology, without being hidden by an apparent horizon. There also exist configurations where a marginally trapped surface with the torus topology forms inside a marginally trapped surface with the spherical topology, showing a further similarity between DTTSs and trapped surfaces.

HOOP CONJECTURE IN NONSPHERICAL SELF-GRAVITATING SYSTEMS

1992 ◽  
Vol 07 (19) ◽  
pp. 1679-1690 ◽  
Author(s):  
EDWARD MALEC
Keyword(s):  
General Framework ◽  
Necessary Condition ◽  
Conformally Flat ◽  
Trapped Surfaces ◽  
Apparent Horizons ◽  
Sectional Curvatures ◽  
Hoop Conjecture ◽  
Gravitating Systems

A general framework for the study of the formation of apparent horizons is found. A necessary condition is given in momentarily static nonspherical geometries with non-negative (locally) sectional curvatures. Known results concerning the existence of trapped surfaces are reviewed in a class of conformally flat nonspherical systems.

scholarly journals Nonlinear dynamics of flux compactification

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Maxence Corman ◽  
William E. East ◽  
Matthew C. Johnson
Keyword(s):  
Flux Compactifications ◽  
Nonlinear Evolution ◽  
Einstein Equations ◽  
Accelerated Expansion ◽  
Positive Cosmological Constant ◽  
Flux Compactification ◽  
Trapped Surfaces ◽  
Slow Roll ◽  
Form Field ◽  
Lower Dimensional

Abstract We study the nonlinear evolution of unstable flux compactifications, applying numerical relativity techniques to solve the Einstein equations in D dimensions coupled to a q-form field and positive cosmological constant. We show that initially homogeneous flux compactifications are unstable to dynamically forming warped compactifications. In some cases, we find that the warping process can serve as a toy-model of slow-roll inflation, while in other instances, we find solutions that eventually evolve to a singular state. Analogous to dynamical black hole horizons, we use the geometric properties of marginally trapped surfaces to characterize the lower dimensional vacua in the inhomogeneous and dynamical settings we consider. We find that lower-dimensional vacua with a lower expansion rate are dynamically favoured, and in some cases find spacetimes that undergo a period of accelerated expansion followed by contraction.

scholarly journals Closed Trapped Surfaces in Cosmology

2003 ◽  
Vol 35 (8) ◽  
pp. 1309-1319 ◽  
Author(s):  
George F. R. Ellis
Keyword(s):  
Trapped Surfaces

scholarly journals Self-Regular Black Holes Quantized by means of an Analogue to Hydrogen Atoms

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chang Liu ◽  
Yan-Gang Miao ◽  
Yu-Mei Wu ◽  
Yu-Hao Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Density ◽  
Hydrogen Atoms ◽  
Quantum Black Hole ◽  
Extreme Black Hole ◽  
Angular Momenta ◽  
Probability Densities ◽  
Hoop Conjecture ◽  
Hole Model

We suggest a quantum black hole model that is based on an analogue to hydrogen atoms. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of nonextreme black holes are given by the probability densities of excited states with no angular momenta. Such an analogue is inclined to adopt quantization of black hole horizons. In this way, the total mass of black holes is quantized. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

The Hoop conjecture on black holes II

1984 ◽  
Vol 102 (8) ◽  
pp. 347 ◽  
Author(s):  
W.B. Bonnor
Keyword(s):  
Black Holes ◽  
Hoop Conjecture

Black Holes and Trapped Surfaces

2010 ◽  
Author(s):  
José M. M. Senovilla ◽  
Alfredo Macias ◽  
Marco Maceda
Keyword(s):  
Black Holes ◽  
Trapped Surfaces
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