I was hoping someone would mention globular clusters! I couldn't find a way to integrate it naturally in my post. I don't see any information about globular cl

I was hoping someone would mention globular clusters! I couldn't find a way to integrate it naturally in my post. I don't see any information about globular cluster movement in that image. Naturally the confinement wouldn't be 100%, and some amount of gravity would still "leak out,"[1] so the mere existence of globular clusters isn't proof one way or another. Surveying globular clusters offers a good test. RG might (or might not) explain why globular clusters are mysteriously 1) preferentially orbiting perpendicular to the primary galaxy's rotation, perhaps due to stability, and 2) preferentially aligned with each-other in their own plane, perhaps due to mutual (lensed) gravitation. Both of these observations are otherwise unexplained (or require numerous free parameters) under dark matter. We won't know until someone does a survey, and probably some simulation work. Sadly MOND soaks up most of the oxygen in the Modified Gravity field, leaving almost none for RG. [1] see Figure 16 https://arxiv.org/pdf/1603.04943.pdf https://arxiv.org/pdf/1603.04943.pdf