Photon motion in Kerr-de Sitter spacetimes

@article{29863,
   author = {Charbulák, Daniel and Stuchlík, Zdeněk},
   article_number = {12},
   doi = {http://dx.doi.org/10.1140/epjc/s10052-017-5401-9},
   keywords = {nonzero cosmological constant; black-hole; naked singularity; radial motion; charged-particles; dark energy; thick discs; orbits; field; time},
   language = {eng},
   issn = {1434-6044},
   journal = {European Physical Journal C},
   title = {Photon motion in Kerr-de Sitter spacetimes},
   url = {https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-017-5401-9},
   volume = {77},
   year = {2017}
}

TY  - JOUR
ID  - 29863
AU  - Charbulák, Daniel - Stuchlík, Zdeněk
PY  - 2017
TI  - Photon motion in Kerr-de Sitter spacetimes
JF  - European Physical Journal C
VL  - 77
IS  - 12
SP  - „897-1“-„897-32“
EP  - „897-1“-„897-32“
SN  - 14346044
KW  - nonzero cosmological constant
KW  - black-hole
KW  - naked singularity
KW  - radial motion
KW  - charged-particles
KW  - dark energy
KW  - thick discs
KW  - orbits
KW  - field
KW  - time
UR  - https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-017-5401-9
L2  - https://link.springer.com/article/10.1140%2Fepjc%2Fs10052-017-5401-9
N2  - We study the general motion of photons in the Kerr-de Sitter black-hole and naked singularity spacetimes. The motion is governed by the impact parameters X, related to the axial symmetry of the spacetime, and q, related to its hidden symmetry. Appropriate "effective potentials" governing the latitudinal and radial motion are introduced and their behavior is examined by the "Chinese boxes" technique giving regions allowed for the motion in terms of the impact parameters. Restrictions on the impact parameters X and q are established in dependence on the spacetime parameters M, Lambda, a. The motion can be of orbital type (crossing the equatorial plane, q > 0) and vortical type (tied above or below the equatorial plane, q < 0). It is shown that for negative values of q, the reality conditions imposed on the latitudinal motion yield stronger constraints on the parameter X than that following from the reality condition of the radial motion, excluding the existence of vortical motion of constant radius. The properties of the spherical photon orbits of the orbital type are determined and used along with the properties of the effective potentials as criteria of classification of the KdS spacetimes according to the properties of the motion of the photon.
ER  - 

CHARBULÁK, Daniel a Zdeněk STUCHLÍK. Photon motion in Kerr-de Sitter spacetimes. \textit{European Physical Journal C}. roč.~77, č.~12, s.~„897-1“-„897-32“, 32 s. ISSN~1434-6044. doi:10.1140/epjc/s10052-017-5401-9. 2017.