scholarly journals Hamiltonian dynamics of Lovelock black holes with spherical symmetry

2013 ◽  
Vol 30 (6) ◽  
pp. 065002 ◽  
Author(s):  
Gabor Kunstatter ◽  
Hideki Maeda ◽  
Tim Taves
Keyword(s):  
Black Holes ◽  
Spherical Symmetry ◽  
Hamiltonian Dynamics

scholarly journals Horizon states and the sign of their index in $$ \mathcal{N} $$ = 4 dyons

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Aradhita Chattopadhyaya ◽  
Justin R. David
Keyword(s):  
Black Holes ◽  
Spherical Symmetry ◽  
Degrees Of Freedom ◽  
Zero Modes

Abstract Classical single centered solutions of 1/4 BPS dyons in $$ \mathcal{N} $$ N = 4 theories are usually constructed in duality frames which contain non-trivial hair degrees of freedom localized outside the horizon. These modes are in addition to the fermionic zero modes associated with broken supersymmetry. Identifying and removing the hair from the 1/4 BPS index allows us to isolate the degrees of freedom associated with the horizon. The spherical symmetry of the horizon then ensures that index of the horizon states has to be positive. We verify that this is indeed the case for the canonical example of dyons in type IIB theory on K3 × T2 and prove this property holds for a class of states. We generalise this observation to all CHL orbifolds, this involves identifying the hair and isolating the horizon degrees of freedom. We then identify the horizon states for 1/4 BPS dyons in $$ \mathcal{N} $$ N = 4 models obtained by freely acting ℤ2 and ℤ3 orbifolds of type IIB theory compactified on T6 and observe that the index is again positive for single centred black holes. This observation coupled with the fact the 1/4 BPS index of single centred solutions without removal of the hair violates positivity indicates that there exists no duality frame in these models without non-trivial hair.

scholarly journals Black hole factory: A review of double-null formalism

2019 ◽  
Vol 28 (03) ◽  
pp. 1930006 ◽  
Author(s):  
Anna Nakonieczna ◽  
Łukasz Nakonieczny ◽  
Dong-Han Yeom
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Spherical Symmetry ◽  
Review Paper ◽  
Black Hole Physics ◽  
Research Areas ◽  
Particle Astrophysics ◽  
Numerical Tool ◽  
Matter Sector

In this review paper, we comprehensively summarize numerical applications of double-null formalism for studying dynamics within the theory of gravity. By using the double-null coordinates, we can investigate dynamical black holes and gravitational phenomena within spherical symmetry, including gravitational collapse, formation of horizons and singularities, as well as evaporations. This formalism can be extended to generic situations, where we can change dimensions, topologies, the gravity sector, as well as the matter sector. We also discuss its possible implications for black hole physics and particle astrophysics. This strong numerical tool will have lots of future applications for various research areas including general relativity, string theory and various approaches to quantum gravity.

scholarly journals THE SPHERICAL SYMMETRY BLACK HOLE COLLAPSE IN EXPANDING UNIVERSE

2012 ◽  
Vol 21 (04) ◽  
pp. 1250039 ◽  
Author(s):  
J. T. FIROUZJAEE
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmological Constant ◽  
Spherical Symmetry ◽  
Tube Surface ◽  
Expanding Universe ◽  
Surface Behavior ◽  
Singularity Line ◽  
Cosmological Black Holes

The spherical symmetry black holes are considered in expanding background. The singularity line and the marginally trapped tube surface behavior are discussed. In particular, we address the conditions whether dynamical horizon forms for these cosmological black holes. We also discuss about the cosmological constant effect on these black hole and the redshift of the light which comes from the marginally trapped tube surface.

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