Stable Schwarzschild stars as black-hole mimickers

@article{36729,
   author = {Konoplya, Roman and Posada Aguirre, Nelson Camilo and Stuchlík, Zdeněk and Zhydenko, Olexandr},
   article_number = {4},
   doi = {http://dx.doi.org/10.1103/PhysRevD.100.044027},
   keywords = {Schwarzschild star; quasinormal modes; black-hole mimicker; stability},
   language = {eng},
   issn = {2470-0010},
   journal = {Physical Review D},
   title = {Stable Schwarzschild stars as black-hole mimickers},
   url = {https://journals.aps.org/prd/abstract/10.1103/PhysRevD.100.044027},
   volume = {100},
   year = {2019}
}

TY  - JOUR
ID  - 36729
AU  - Konoplya, Roman - Posada Aguirre, Nelson Camilo - Stuchlík, Zdeněk - Zhydenko, Olexandr
PY  - 2019
TI  - Stable Schwarzschild stars as black-hole mimickers
JF  - Physical Review D
VL  - 100
IS  - 4
SP  - "044027-1"-"044027-7"
EP  - "044027-1"-"044027-7"
SN  - 24700010
KW  - Schwarzschild star
KW  - quasinormal modes
KW  - black-hole mimicker
KW  - stability
UR  - https://journals.aps.org/prd/abstract/10.1103/PhysRevD.100.044027
L2  - https://journals.aps.org/prd/abstract/10.1103/PhysRevD.100.044027
N2  - The Schwarzschild star is an ultracompact object beyond the Buchdahl limit, which has Schwarzschild geometry outside its surface and positive pressure in the external layer which vanishes at the surface. Recently, it has been shown that the Schwarzschild star is stable against spherically symmetric perturbations. Here we study arbitrary axial nonspherical perturbations and show that the observable quasinormal modes can be as close to the Schwarzschild limit as one wishes, what makes the Schwarzschild star a very good mimicker of a black hole. The decaying time-domain profiles prove that the Schwarzschild star is stable against nonspherical perturbations as well. Another peculiar feature is the absence of echoes at the end of the ringdown. Instead we observe a nonoscillating mode which might belong to the class of algebraically special modes. At asymptotically late times, Schwarzschildian power-law tails dominate in the signal.
ER  - 

KONOPLYA, Roman, Nelson Camilo POSADA AGUIRRE, Zdeněk STUCHLÍK and Olexandr ZHYDENKO. Stable Schwarzschild stars as black-hole mimickers. \textit{Physical Review D}. 2019, vol.~100, No~4, p.~''044027-1''-''044027-7'', 7 pp. ISSN~2470-0010. Available from: https://dx.doi.org/10.1103/PhysRevD.100.044027.