Thanks all — that answers my curiosity. I see now that in standard GR the “2” is fixed by the Newtonian limit and shows up in the horizon area as part of the usual geometry, not from any deeper topological principle. That was exactly what I wanted to check.
Even if that doesn’t fully satisfy...
Thanks, that’s a fair question. The reason I asked is because I ended up with this factor of 2 showing up in a calculation of mine, and it looked a bit too perfect to just ignore. It made me wonder if there was any known geometric or topological explanation for it, or if the consensus is that...
I am exploring the topological reasons behind certain physical constants. In GR, is the factor of 2 in the Schwarzschild radius (Rs=2GM/c^2) ever treated as having a deeper topological significance?