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HK: Fachverband Physik der Hadronen und Kerne
HK 31: Nuclear Astrophysics II
HK 31.2: Talk
Tuesday, March 12, 2024, 18:00–18:15, HBR 19: C 103
Generating ultra compact boson stars with modified scalar potentials — •Sarah Louisa Pitz and Jürgen Schaffner-Bielich — Goethe Universität, Frankfurt am Main, Deutschland
The properties of self-interacting boson stars with different scalar potentials going beyond the commonly used φ4 ansatz are studied. The scalar potential is extended to different values of the exponent n of the form V ∝ φn. Two stability mechanism for boson stars are introduced, the first being a mass term and the second one a vacuum term. In this talk analytic scale-invariant expressions for these two classes of equations of state are presented. The resulting properties of the boson star configurations differ considerably from previous calculations. The maximal compactness can reach extremely high values going to the limit of causality Cmax = 0.354 asymptotically for n→∞. The maximal compactnesses exceed previously calculated values of Cmax=0.16 for the standard φ4-theory and Cmax=0.21 for vector-like interactions and is in line with previous results for solitonic boson stars. Hence, boson stars even described by a simple modified scalar potential in the form of V ∝ φn can be ultra compact black hole mimickers where the photon ring is located outside the radius of the star.
Keywords: Dark matter; General relativity