Kinetic relaxation and nucleation of Bose stars in self-interacting wave dark matter

Journal Article · 01 January 2024 · Physical Review. D.

DOI: https://doi.org/10.1103/PhysRevD.109.016002 · OSTI ID:2274866

Jain, Mudit ; Wanichwecharungruang, Wisha ; Thomas, Jonathan

We revisit kinetic relaxation and soliton/boson star nucleation in fuzzy scalar dark matter featuring short-ranged self-interactions ${\mathcal{H}}_{\mathrm{int}}=-\lambda |\psi {|}^4/2m^2$ , alongside gravitational self-interactions. We map out the full curve of nucleation timescale for both repulsive ( $\lambda <0$ ) and attractive ( $\lambda >0$ ) short-ranged self-interaction strength and in doing so reveal two new points. Firstly, besides the two usual terms, $\propto G^2$ and $\propto {\lambda }^2$ , in the total relaxation rate ${\mathrm{\Gamma }}_{\text{relax}}$ , there is an additional cross term $\propto G\lambda$ arising due to interference between gravitational and short-ranged self-interaction scattering amplitudes. This yields a critical repulsive interaction strength ${\lambda }_{\mathrm{cr}}\simeq -2\pi G{m}^2/v_0^2$ , at which the relaxation rate is smallest and serves as the transition point between typical net attractive self-interaction ( $\lambda \gtrsim {\lambda }_{\mathrm{cr}}$ ) and net repulsive self-interaction ( $-\lambda \gtrsim -{\lambda }_{\mathrm{cr}}$ ). Secondly, while in the net attractive regime, nucleation timescale is similar to inverse relaxation timescale ${\tau }_{\mathrm{nuc}}\sim {\mathrm{\Gamma }}_{\text{relax}}^{-1}$ ; in the net repulsive regime, nucleation occurs at a delayed time ${\tau }_{\mathrm{nuc}}\sim (\lambda /{\lambda }_{\mathrm{cr}}){\mathrm{\Gamma }}_{\text{relax}}^{-1}$ . We confirm our analytical understanding by performing 3D field simulations with varying average mass density $\overline{\rho }$ , box size $L$ and grid size $N$ . Published by the American Physical Society 2024

• Research Organization: Rice Univ., Houston, TX (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC)
• Grant/Contract Number: SC0021619
• OSTI ID: 2274866
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 1 Vol. 109; ISSN PRVDAQ; ISSN 2470-0010
• Publisher: American Physical SocietyCopyright Statement
• Country of Publication: United States
• Language: English