Thank you for your answer.

I guess, that the intention of the paper is, to give a physical substantiation for world-trajectories like those constructed in the deBroglie-Bohm theory. This substantiation must yield results consistent with the many-particle Schroedinger-Equation - as the deBroglie-Bohm theory does. To get Born's Rule for the trajectories, the authors think of the trajectories as virtually infinitely many but countable flowing worldpoints in the configuration-space. As I understand you, in a fluid in higher dimensions vortices are possible. In my opinion, vortices in a fluid are in contradiction to quantum mechanics i.e. the many-particle Schroedinger-Equation, while deBroglie-Bohm theory is not.

Is a world moving through configurationspace necessarily connected to a moving configurationspace worldpoint, or is the identity of a moving world like the identity of a wave, which exchanges the matter it runs through but keeps its identity? Here this "matter" is made of configurationspace worldpoints. The interesting question is: would such a wave also fullfil Born's Rule, because it consists of many worldpoints? This would lead to a worldpoint-ether more like a rigid body than like a fluid.

Yes, you are right, there are many vortices . To build a usual vortex in 3D-space a lot of particles are interacting for example via electromagnetic forces. In the model discussed here worldpoints interact in configurationspace via the new hypothetic force and eventually can build vortices in configurationspace. So particles without conventional physical interaction (i.e. electromagnetic forces, gravity etc.) can build vortices in configurationspace. And they would look in normal 3D-space as vortices or at least as arbitrary movements - but without interactions! May be, that I overemphasize vortices - phenomenological I expect fluid-like movements but without forces/interactions. What is your opinion?

Thank you for your link, I enjoyed it much.

In my reasoning, I consider a location in space where are no interactions via conventional forces, therefore as well no reason for a mean-field. At such a place, there could be some arbitrary fluid-like movements based on the new hypothetical force between the worldpoints. Think for example about the double-slit experiment: an experiment with conventional forces and a force free region behind the slit, where the particles evolve wavelike. In the force free region fluid-like movements- especially vortices-  would disturb the interference-pattern.