1998/06/04 by J. Novak, J. Novák · 6 citations
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Pulsars and Gravitational Waves Research #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.58.064019
published as Phys.Rev. D58 (1998) 064019 · 14 pages, 10 figures, accepted for publication in Physical Review D
arxiv created 1998/06/04 · openalex publication_date 1998/08/27 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Spherical neutron star models are studied within tensor-scalar theories of gravity. Particularly, it is shown that, under some conditions on the second derivative of the coupling function and on the star's mass, for a given star there exist two strong-scalar-field solutions as well as the usual weak-field one. This last solution happens to be unstable and a star, becoming massive enough to allow for all three solutions, evolves to reach one of the strong field configurations. This transition is dynamically computed and it appears that the star radiates away the difference in energy between both states (a few 10^\ensuremath-3M_\ensuremath\bigodotc2) as gravitational radiation. Since part of the energy (\ensuremath∼10^\ensuremath-5M_\ensuremath\bigodotc2) is injected into the star as kinetic energy, the velocity of the star's surface can reach up to 10^\ensuremath-2c. The waveform of this monopolar radiation is shown as well as the oscillations undergone by the star. These oscillations are also studied within the slowly rotating approximation, in order to estimate an order of magnitude of the resulting quadrupolar radiation.