On the radial stability of ultra-compact Schwarzschild stars beyond the Buchdahl limit

@article{37791,
   author = {Posada Aguirre, Nelson Camilo and Chirenti, Cecilia},
   article_number = {6},
   doi = {http://dx.doi.org/10.1088/1361-6382/ab0526},
   keywords = {ultra-compact stars; radial oscillations; stellar stability; interior solution},
   language = {eng},
   issn = {0264-9381},
   journal = {Classical and Quantum Gravity},
   title = {On the radial stability of ultra-compact Schwarzschild stars beyond the Buchdahl limit},
   url = {https://iopscience.iop.org/article/10.1088/1361-6382/ab0526},
   volume = {36},
   year = {2019}
}

TY  - JOUR
ID  - 37791
AU  - Posada Aguirre, Nelson Camilo - Chirenti, Cecilia
PY  - 2019
TI  - On the radial stability of ultra-compact Schwarzschild stars beyond the Buchdahl limit
JF  - Classical and Quantum Gravity
VL  - 36
IS  - 6
SP  - "065004-1"-"065004-14"
EP  - "065004-1"-"065004-14"
SN  - 02649381
KW  - ultra-compact stars
KW  - radial oscillations
KW  - stellar stability
KW  - interior solution
UR  - https://iopscience.iop.org/article/10.1088/1361-6382/ab0526
L2  - https://iopscience.iop.org/article/10.1088/1361-6382/ab0526
N2  - In this paper we used the theory of adiabatic radial oscillations developed by Chandrasekhar to study the conditions for dynamical stability of constant energy-density stars, or Schwarzschild stars, in the unstudied ultra compact regime beyond the Buchdahl limit, that is, for configurations with radius R in the range R_S < R < (9/8)R_S, where R_S is the Schwarzschild radius of the star. These recently found analytical solutions exhibit a negative pressure region in their centre and, in the limit when R -> R_S, the full interior region of the star becomes filled with negative pressure. Here we present a systematic analysis of the stability of these configurations against radial perturbations. We found that, contrary to the usual expectation found in many classical works, the ultra compact Schwarzschild star is stable against radial oscillations. We computed values of the critical adiabatic index gamma_(c) for several stellar models with varying radius R/R_s and found that it also approaches a finite value as R/R_S -> 1.
ER  - 

POSADA AGUIRRE, Nelson Camilo a Cecilia CHIRENTI. On the radial stability of ultra-compact Schwarzschild stars beyond the Buchdahl limit. \textit{Classical and Quantum Gravity}. 2019, roč.~36, č.~6, s.~''065004-1''-''065004-14'', 14 s. ISSN~0264-9381. Dostupné z: https://dx.doi.org/10.1088/1361-6382/ab0526.