Gravastar Star With no Horizon with ultracompact and very density possible?
Of course unknown "strange Quantum Effects" could do anything, but this letter reports calculations which suggest that at least one of the LIGO gravitational wave events is consistent with black holes but not with gravastars. That doesn't rule out the possibility of gravastars and black holes existing, but it speaks quite strongly against the idea that all the phenomena attributed to black holes are actually due to gravastars.