Have any papers been published concerning BH's on membranes (superstring) vs non-string universe? My questions are: 1. if we have a membranous universe/dimension then all angles of approach to a BH lead to its critical circumference so you cannot sneak up on it so to speak. = Questions: (a) there is a BH throat: (b) how long must it be? (c) any slope defined of diminishing size? (d) Does spin continue all the way down or would "final gravity strength" at some point straighten out any gravitational or magnetic lines from swirling? (e) If our singularity empties into another universe/dimension are we intruding another universe/dimension into one already extant (ramifications?) or is it, as it enters, one tiny BH that explodes with no consequence to the intruded-into universe/dimension (like the early Big Bang mini-BH's)? 2.That conversely might say that if the universe is not membranous, then the BH must have a spherical shape which says the singularity is a core and therefore the BH is like a planetary body with its entire surface being a horizon and the entire body may or may not shrink. Is there a backside you might say. Anyone published on the 360 degree-ness of a black hole or not? Any of these types of questions been researched? I can find nothing.