NOTES
And here’s the force along the Ring (towards the centerline of the Ring), in blue (evaluated at the surface of the Ring). Note that the force towards the center due to the Ring gravity is about a third of the force due to solar tides – so it looks like the mass on the inside of the Ring is curved more than than I calculated before, but I haven’t done the math on this yet. To be really complete, I should take into account the non-linear effect – as the material on the Ring gets clumped in the middle, there’s a tendency to get more clumped, but that’s for another day, too.