## Abstract

We investigate the instability driven by viscosity in rotating relativistic stars by means of an iterative approach. We focus on polytropic rotating equilibrium stars and impose an m=2 perturbation in the lapse. We vary both the stiffness of the equation of state and the compactness of the star to study these factors on the critical value T/W for the instability. For a rigidly rotating star, the criterion T/W, where T is the rotational kinetic energy and W the gravitational binding energy, mainly depends on the compactness of the star and takes values around 0.13-0.16, which slightly differ from that of Newtonian incompressible stars (∼0.14). For differentially rotating stars, the critical value of T/W is found to span the range 0.17-0.25. The value is significantly larger than in the rigidly rotating case with the same compactness of the star. Finally we discuss the possibility of detecting gravitational waves from viscosity-driven instabilities using ground-based interferometers.

Original language | English |
---|---|

Pages (from-to) | 481-485 |

Number of pages | 5 |

Journal | Astrophysics and Space Science |

Volume | 308 |

Issue number | 1-4 |

DOIs | |

Publication status | Published - 2007 Apr |

Externally published | Yes |

## Keywords

- Gravitational waves
- Instabilities
- Relativity
- Stars: rotation

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science