Spherical photon orbits in the field of Kerr naked singularities
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19240%2F18%3AA0000245" target="_blank" >RIV/47813059:19240/18:A0000245 - isvavai.cz</a>
Result on the web
<a href="https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-018-6336-5" target="_blank" >https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-018-6336-5</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1140/epjc/s10052-018-6336-5" target="_blank" >10.1140/epjc/s10052-018-6336-5</a>
Alternative languages
Result language
angličtina
Original language name
Spherical photon orbits in the field of Kerr naked singularities
Original language description
For the Kerr naked singularity (KNS) spacetimes, we study properties of spherical photon orbits (SPOs) confined to constant Boyer-Lindquist radius r. Some new features of the SPOs are found, having no counterparts in the Kerr black hole (KBH) spacetimes, especially stable orbits that could be pure prograde/retrograde, or with turning point in the azimuthal direction. At r > 1 (r < 1) the covariant photon energy E > 0 (E < 0), at r = 1 there is E = 0. All unstable orbits must have E > 0. It is shown that the polar SPOs can exist only in the spacetimes with dimensionless spin a < 1.7996. Existence of closed SPOs with vanishing total change of the azimuth is demonstrated. Classification of the KNS and KBH spacetimes in dependence on their dimensionless spin a is proposed, considering the properties of the SPOs. For selected types of the KNS spacetimes, typical SPOs are constructed, including the closed paths. It is shown that the stable SPOs intersect the equatorial plane in a region of stable circular orbits of test particles, depending on the spin a. Relevance of this intersection for the Keplerian accretion discs is outlined and observational effects are estimated.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GJ16-03564Y" target="_blank" >GJ16-03564Y: Accretion configurations in strong gravity combined with electromagnetic field</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Physical Journal C
ISSN
1434-6044
e-ISSN
1434-6052
Volume of the periodical
78
Issue of the periodical within the volume
11
Country of publishing house
US - UNITED STATES
Number of pages
25
Pages from-to
„879-1“-„879-25“
UT code for WoS article
000448860000004
EID of the result in the Scopus database
2-s2.0-85056110132