Fetching the paper…
Reading the bibliography…
The Kerr black holes possess a photon region with prograde and retrograde orbits radii, respectively, $M\leq r_p^-\leq 3M$ and $3M\leq r_p^+\leq 4M$, and thereby always cast a closed photon ring or a shadow silhouette for $a\leq M$.
R. P. Kerr, Phys. Rev. Lett
1963
Earlier work this paper cites.
E. T. Newman, R. Couch, K. Chinnapared, A. Exton, A. Prakash and R. Torrence, J. Math. Phys
1965
Earlier work this paper cites.
J. L. Synge, Mon. Not. R. Astron. Soc
1966
Earlier work this paper cites.
A. D. Sakharov, Sov. Phys. JETP
1966
Earlier work this paper cites.
E. B. Gliner, JETP
1966
Earlier work this paper cites.
J. M. Bardeen, in Conference Proceedings of GR5, Tbilisi, URSS, p. 174 (1968)
1968
Earlier work this paper cites.
B. Carter, Phys. Rev. D
1968
Earlier work this paper cites.
C. T. Cunningham, J. M. Bardeen, Astrophys. J
1972
Earlier work this paper cites.
J. M. Bardeen, W. H. Press and S. A. Teukolsky, Astrophys. J
1972
Earlier work this paper cites.
D. C. Wilkins, Phys. Rev. D
1972
Earlier work this paper cites.
J. M. Bardeen,
1973
Earlier work this paper cites.
J. P. Luminet, Astron. Astrophys
1979
Earlier work this paper cites.
I. H. Salazar, A. Garcia and J. Plebanski, J. Math. Phys
1987
Earlier work this paper cites.
S. Chandrasekhar,
1992
Earlier work this paper cites.
H. Falcke, F. Melia and E. Agol, Astrophys. J
2000
Earlier work this paper cites.
E. Ayon-Beato and A. Garcia, Phys. Lett. B
2000
Earlier work this paper cites.
K. A. Bronnikov, Phys. Rev. Lett
2000
Earlier work this paper cites.
A. de Vries, Class. Quant. Grav
2000
Earlier work this paper cites.
K. A. Bronnikov, Phys. Rev. D
2001
Earlier work this paper cites.
2002
Earlier work this paper cites.
R. Penrose, Riv. Nuovo Cim
2002
Earlier work this paper cites.
E. Teo, Gen. Relativ. Gravit. 35, 1909 (2003)
2003
Earlier work this paper cites.
R. Takahashi, J. Korean Phys. Soc
2004
Earlier work this paper cites.
E. Ayon-Beato and A. Garcia, Phys. Rev. Lett
2004
Earlier work this paper cites.
K. Beckwith and C. Done, Mon. Not. Roy. Astron. Soc
2005
Earlier work this paper cites.
S. A. Hayward, Phys. Rev. Lett
2006
Cited alongside, same era.
K. Hioki and K. i. Maeda, Phys. Rev. D
2009
Cited alongside, same era.
Z. Q. Shen, K.Y. Lo, M. C. Liang, P. T. P. Ho and J. H. Zhao, Nature
2010
Cited alongside, same era.
T. Johannsen and D. Psaltis, Astrophys. J
2010
Cited alongside, same era.
T. Johannsen, Astrophys. J
2013
Cited alongside, same era.
S. H. Hendi, Annals Phys
2013
Cited alongside, same era.
C. Bambi and L. Modesto, Phys. Lett. B
2013
Cited alongside, same era.
S. I. Kruglov, Annals Phys
2017
Later among the works it cites.
B. Toshmatov, Z. Stuchlik and B. Ahmedov, Phys. Rev. D
2017
Later among the works it cites.
P. V. P. Cunha, C. A. R. Herdeiro, B. Kleihaus, J. Kunz and E. Radu, Phys. Lett. B
2018
Later among the works it cites.
P. V. P. Cunha and C. A. R. Herdeiro, Gen. Rel. Grav
2018
Later among the works it cites.
P. V. P. Cunha, C. A. R. Herdeiro and M. J. Rodriguez, Phys. Rev. D
2018
Later among the works it cites.
Z. Y. Fan and X. Wang, Phys. Rev. D
2018
Later among the works it cites.
J. Schee and Z. Stuchlík, Class. Quant. Grav
2018
alphaXiv searches the wider corpus for related work and actual follow-ups.
alphaXiv is searching for related work…
Z. Li and C. Bambi, Phys. Rev. D
2013
Cited alongside, same era.
M. Azreg-Aïnou, Phys. Rev. D
2014
Cited alongside, same era.
B. Toshmatov, B. Ahmedov, A. Abdujabbarov and Z. Stuchlik, Phys. Rev. D
2014
Cited alongside, same era.
Z. Li and C. Bambi, J. Cosmol. Astropart. Phys
2014
Cited alongside, same era.
M. Azreg-Aïnou, Eur. Phys. J. C
2014
Cited alongside, same era.
Later among the works it cites.
F. Lamy, E. Gourgoulhon, T. Paumard and F. H. Vincent, Class. Quant. Grav
2018
Later among the works it cites.
N. Tsukamoto, Phys. Rev. D
2018
Later among the works it cites.
D. Charbulak and Z. Stuchlik, Eur. Phys. J. C
2018
Later among the works it cites.
R. Shaikh, P. Banerjee, S. Paul and T. Sarkar, Phys. Rev. D
2019
Later among the works it cites.
K. Akiyama
2019
Later among the works it cites.
K. Akiyama
2019
Later among the works it cites.
K. Akiyama
2019
Later among the works it cites.
R. Kumar, S. G. Ghosh and A. Wang, Phys. Rev. D
2019
Later among the works it cites.
R. Shaikh, P. Kocherlakota, R. Narayan and P. S. Joshi, Mon. Not. Roy. Astron. Soc
2019
Later among the works it cites.
R. Shaikh and P. S. Joshi, JCAP
2019
Later among the works it cites.
P. V. P. Cunha and C. A. R. Herdeiro, Phys. Rev. Lett
2020
Closest in time.
P. V. P. Cunha, C. A. R. Herdeiro and E. Radu, Universe
2020
Closest in time.
A. B. Joshi, D. Dey, P. S. Joshi and P. Bambhaniya, Phys. Rev. D
2020
Closest in time.
R. Kumar, A. Kumar and S. G. Ghosh, Astrophys. J
2020
Closest in time.
S. E. Gralla and A. Lupsasca, Phys. Rev. D
2020
Closest in time.
A. Simpson and M. Visser, Universe, 6, 8 (2020)
2020
Closest in time.
R. Kumar and S. G. Ghosh, Astrophys. J
2020
Closest in time.