Solitonic axion condensates modeling dark matter halos

Increased infall velocities in galaxy clusters from solitonic collisions?

“…The Musket ball clusters appear much older [37] and slower. Thus, the intrinsic mechanism [6,25] of temporarily "sticky" solitons during the non-Newtonian scattering process could, to some extent, explain the enhanced infall velocity of the bullet cluster, taking into consideration that the dimensionless displacement 2δ has to be multiplied by the Compton wave length λ Compton of axionlike particles.…”

“…Observations of astrophysical collisions such as merging clusters provide a valuable test of alternatives to CDM. In particular, we continue our investigation [6] whether or not two dark matter halos, pulling towards one another, can be modeled via soliton-type collisions without invoking [7] a dark energy (DE) mediating "fifth force." The (phase) displacement of two colliding solitons, to some extent, resembles the effects of such a hypothetical force not observed in the laboratory [8].…”

“…12 of Ref. [6], which cannot easily be confounded with domain walls. More than a century ago, it was considered as a crude model for the density of the sun and a bit later for the distribution of stars in globular clusters.…”

“…Since the DM distributions in the bullet cluster appear not to be affected during merging, we postulate an axionlike scalar component of galaxies and clusters and analyze its solitary wave behavior, or as in our previous two-dimensional toy model [6], its Lane-Emden (LE) truncation [10],…”