After the duality revolution, we learned about the important role of both, black p-branes and p-branes. However, sometimes their fundamental definition is confused in the literature. I mean the following:
Black p-brane: solitonic solution to (super)gravity field equations (and / or superstring/supergravity theories), describing a black hole with p-spatial dimensions.
Fundamental p-branes: p-dimensional extended object, described by a Nambu-Goto action (or any other action equivalent at the level of the equation of motion, e.g., the Howe-Tucker action).
- Is any black brane fundamental somehow, and so, can it be described by some kind of Nambu-Goto action (or Polyakov-like, etc), and viceversa, ...Can we consider any fundamental p-brane like some kind of "black-hole"-like solution? I have never read a clarification of this stuff in the literature, at least, not in a transparent way. In particular, I can not see any reason why the Nambu-Goto action is relevant to black hole p-branes, BUT, seemingly, the counting of Dp-branes providing the BH entropy in some BH solutions supports the idea of having fundamental p-branes as degrees of freedom entangled with this problem. I am not sure, however, of the equivalence or not of these objects.