THE UNBEARABLE BEINGNESS OF LIGHT — Dressingand Undressing Photonsin Black Hole Spacetimes

Gravitational tidal forces acting on the virtual e+e- cloud surrounding a photon endow spacetime with a nontrivial refractive index. This has remarkable properties unique to gravitational theories including superluminal low-frequency propagation, in apparent violation of causality, and amplification of the renormalized photon field, in apparent violation of unitarity. Using the geometry of null congruences and the Penrose limit, we illustrate these phenomena and their resolution by tracing the history of a photon as it falls into the near-singularity region of a black hole.

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A Brief Observational History of the Black-Hole Spacetimes

Advances in Mathematical Physics ◽

10.1155/2015/617128 ◽

2015 ◽

Vol 2015 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Wolfgang Kundt

Keyword(s):

Black Holes ◽

Black Hole ◽

Vacuum Solution ◽

Albert Einstein ◽

Spherically Symmetric ◽

100Th Birthday ◽

Black Hole Spacetimes ◽

History Of ◽

Symmetric Vacuum

In this year (2015), black holes (BHs) celebrate their 100th birthday, if their birth is taken to be triggered by a handwritten letter from Martin Schwarzschild to Albert Einstein, in connection with his newly found spherically symmetric vacuum solution.

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TIDAL FORCES IN COLD BLACK HOLE SPACETIMES

International Journal of Modern Physics D ◽

10.1142/s0218271801001050 ◽

2001 ◽

Vol 10 (04) ◽

pp. 529-538 ◽

Cited By ~ 10

Author(s):

K. K. NANDI ◽

T. B. NAYAK ◽

A. BHADRA ◽

P. M. ALSING

Keyword(s):

Black Holes ◽

Black Hole ◽

Spherically Symmetric ◽

Black Hole Spacetimes ◽

Tidal Forces ◽

Black Hole Solutions

We investigate here the behavior of a few spherically symmetric static acclaimed black hole solutions in respect of tidal forces in the geodesic frame. It turns out that the forces diverge on the horizon of cold black holes (CBH) while for ordinary ones, they do not. It is pointed out that Kruskal-like extensions do not render the CBH metrics nonsingular. We present a CBH that is available in the Brans–Dicke theory for which the tidal forces do not diverge on the horizon and in that sense it is a better one.

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Tidal forces near a black hole with scalar hairy

Journal of Physics Conference Series ◽

10.1088/1742-6596/1690/1/012181 ◽

2020 ◽

Vol 1690 ◽

pp. 012181

Author(s):

E L Andre ◽

I M Potashov ◽

Ju V Tchemarina ◽

A N Tsirulev

Keyword(s):

Black Hole ◽

Tidal Forces

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Modification to the Hawking temperature of a dynamical black hole by a flow-induced supertranslation

Journal of High Energy Physics ◽

10.1007/jhep12(2020)089 ◽

2020 ◽

Vol 2020 (12) ◽

Author(s):

Hsu-Wen Chiang ◽

Yu-Hsien Kung ◽

Pisin Chen

Keyword(s):

Black Hole ◽

Coordinate Transformation ◽

Information Loss ◽

Hawking Temperature ◽

Asymptotic Region ◽

Unruh Effect ◽

Anisotropic Flow ◽

Information Loss Paradox ◽

History Of ◽

Entire History

Abstract One interesting proposal to solve the black hole information loss paradox without modifying either general relativity or quantum field theory, is the soft hair, a diffeomorphism charge that records the anisotropic radiation in the asymptotic region. This proposal, however, has been challenged, given that away from the source the soft hair behaves as a coordinate transformation that forms an Abelian group, thus unable to store any information. To maintain the spirit of the soft hair but circumvent these obstacles, we consider Hawking radiation as a probe sensitive to the entire history of the black hole evaporation, where the soft hairs on the horizon are induced by the absorption of a null anisotropic flow, generalizing the shock wave considered in [1, 2]. To do so we introduce two different time-dependent extensions of the diffeomorphism associated with the soft hair, where one is the backreaction of the anisotropic null flow, and the other is a coordinate transformation that produces the Unruh effect and a Doppler shift to the Hawking spectrum. Together, they form an exact BMS charge generator on the entire manifold that allows the nonperturbative analysis of the black hole horizon, whose surface gravity, i.e. the Hawking temperature, is found to be modified. The modification depends on an exponential average of the anisotropy of the null flow with a decay rate of 4M, suggesting the emergence of a new 2-D degree of freedom on the horizon, which could be a way out of the information loss paradox.

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Stable circular orbits in Kaluza-Klein black hole spacetimes

Physical Review D ◽

10.1103/physrevd.103.124004 ◽

2021 ◽

Vol 103 (12) ◽

Author(s):

Shinya Tomizawa ◽

Takahisa Igata

Keyword(s):

Black Hole ◽

Circular Orbits ◽

Black Hole Spacetimes ◽

Kaluza Klein

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Nucleotide Variation at theCHALCONE ISOMERASELocus inArabidopsis thaliana

Genetics ◽

10.1093/genetics/155.2.863 ◽

2000 ◽

Vol 155 (2) ◽

pp. 863-872 ◽

Cited By ~ 14

Author(s):

Helmi Kuittinen ◽

Montserrat Aguadé

Keyword(s):

Nucleotide Diversity ◽

Direct Relationship ◽

Selective Sweep ◽

Balancing Selection ◽

Neutral Theory ◽

Low Frequency ◽

The Other ◽

Nucleotide Variation ◽

Rapid Population Growth ◽

History Of

AbstractAn ~1.9-kb region encompassing the CHI gene, which encodes chalcone isomerase, was sequenced in 24 worldwide ecotypes of Arabidopsis thaliana (L.) Heynh. and in 1 ecotype of A. lyrata ssp. petraea. There was no evidence for dimorphism at the CHI region. A minimum of three recombination events was inferred in the history of the sampled ecotypes of the highly selfing A. thaliana. The estimated nucleotide diversity (θTOTAL = 0.004, θSIL = 0.005) was on the lower part of the range of the corresponding estimates for other gene regions. The skewness of the frequency spectrum toward an excess of low-frequency polymorphisms, together with the bell-shaped distribution of pairwise nucleotide differences at CHI, suggests that A. thaliana has recently experienced a rapid population growth. Although this pattern could also be explained by a recent selective sweep at the studied region, results from the other studied loci and from an AFLP survey seem to support the expansion hypothesis. Comparison of silent polymorphism and divergence at the CHI region and at the Adh1 and ChiA revealed in some cases a significant deviation of the direct relationship predicted by the neutral theory, which would be compatible with balancing selection acting at the latter regions.

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