In the context of formation of large-scale structures, there would be a turnaround radius where expanding matter would detach from the Hubble flow and start to collapse (https://www.aanda.org/articles/aa/full_html/2020/07/aa37337-19/aa37337-19.html)
However, as I understand it, the turnaround radius is related to the mass contained in the overdensity. If there was some huge high-density zone that collapsed very fast, then the total "mass" that would attract the farther regions in the overdensity (in the outskirts) would be bigger.
Then, would the turnaround radius increase, as the collapsed region attracted more mass that would be further away from the radius?
