A few questions for people who know how to answer these things and are able to do these kinds of calculations.

What would the distribution of gravity be if we took the total (non dark matter) mass of a galaxy and converted that value into a probability wave centered on the central black hole? Is that a doable calculation? Has this been done before?

I'm wondering if the distribution of gravity would look different and perhaps account for what we think is the dark matter halo that all galaxies seem to have.

It may not be as simple as just taking the total normal mass and thinking of it as a point-like particle however. It may be that the we have to take the total visible mass distribution (which would be a wave itself since there is a much higher density of mass at the center of a galaxy than at it's edges) and apply the probability wave to that. Then apply gravity to that so that we see what the probable gravity would be for that wave.

Any takers?