2007/10/31 by Jayashree Balakrishna, R. Bondarescu, Ruxandra Bondarescu +2 · 2 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research #gr-qc
paper · pdf · doi:10.1103/physrevd.77.024028
published as Phys.Rev.D77:024028,2008 · 12 pages, 11 figures, typos corrected, includes referee input, references corrected, published version
openalex publication_date 2008/01/16 · arxiv created 2008/01/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Excited state soliton stars are studied numerically for the first time. The stability of spherically symmetric S-branch excited state oscillatons under radial perturbations is investigated using a 1D code. We find that these stars are inherently unstable either migrating to the ground state or collapsing to black holes. Higher excited state configurations are observed to cascade through intermediate excited states during their migration to the ground state. This is similar to excited state boson stars [J. Balakrishna, E. Seidel, and W.-M. Suen, Phys. Rev. D 58, 104004 (1998).]. Ground state oscillatons are then studied in full 3D numerical relativity. Finding the appropriate gauge condition for the dynamic oscillatons is much more challenging than in the case of boson stars. Different slicing conditions are explored, and a customized gauge condition that approximates polar slicing in spherical symmetry is implemented. Comparisons with 1D results and convergence tests are performed. The behavior of these stars under small axisymmetric perturbations is studied and gravitational waveforms are extracted. We find that the gravitational waves damp out on a short time scale, enabling us to obtain the complete waveform. This work is a starting point for the evolution of real scalar field systems with arbitrary symmetries.