Galactic core-tail structure in BEC dark matter with Kapitza potential

TL;DR

This work investigates Bose-Einstein condensate dark matter halos endowed with a Kapitza-type potential to generate core-tail halo structures. By reformulating the GP-Poisson system via Madelung hydrodynamics and adopting a solitonic core with a dynamically evolved tail, the authors fit rotation curves from the SPARC catalogue and benchmark against NFW, Einasto, and Burkert profiles. The Kapitza term provides an additional handle to shape the outer halo and orbital velocities, expanding the space of viable DM halo solutions. Limitations include an unclear physical origin for the Kapitza potential in astrophysical contexts and tail oscillations that require further study, with future work aiming at broader parameter exploration and comparisons to fully numerical simulations.

Abstract

Recently, the experimental realization of a Kapitza potential in a Bose-Einstein Condensate (BEC) has been reported for the first time in literature, motivating further theoretical investigations of such system. At the same time, in the astrophysical context, BEC dark matter models have been widely studied as a possible phenomenological explanation for the dark matter phenomena. We model the galactic structure with an inner cored profile obtained from the ground state equilibrium solution of the Schroedinger-Poisson together with a Kapitza-BEC like interaction for the tail region. We find reasonable agreement of the model with representative galaxy rotation curves available in the SPARC catalogue.

Figures (3)

• Figure 1: Rotation curves (left panels) and density profiles in log-log scale (right panels) for the galaxies analyzed. The NFW, Einasto, Burkert profiles and the solitonic core-tail model are shown. The dashed line indicates the transition radius $r_t$. The adjusted parameters are listed in Table \ref{['table1']}.
• Figure 2: Same as Figure \ref{['galaxies1']} for different galaxies.
• Figure 3: Rotation curve of the galaxy NGC 2903 fitted by the core-tail model. The part $r < r_t$ corresponds to the solitonic core, while $r \geq r_t$ corresponds to the numerical tail solution, shown for different values of $\epsilon$ in the left panel and for different values of $V_{0\mathrm{Kap}}$ in the right panel. The dashed vertical line indicates the transition radius $r_t$. In both panels, the remaining reference values for the parameters are those presented in Table \ref{['table1']}. In each isolated variation, whether of $\epsilon$ or $V_{0\mathrm{Kap}}$, all other parameters remain fixed at the values in the table.