Dear all, recently I'm reading up some string/M-theory, especially the role of branes, because I'm writing a popular science book in Dutch. Every textbook states the issues one encounters when you try to quantize p-branes for p>1, as is discussed e.g. here: https://www.physicsforums.com/threads/issue-with-quantized-branes.389438/ Like 1) non-renormalizability 2) continuous particle spectrum 3) existence of spikes which result in non-locality So, the moral then is: strings are magic, strings it will be. But later in the story branes re-enter the game, via D-branes and e.g. 2- and 5-branes in D=11 sugra and M-theory. So my questions are: *) What happens to the objections we had which made us to prefer strings above p>1-branes and reject them? Why can we suddenly consider branes to be consistent after all? Does it have to do with their solitonic character instead of being fundamental objects like strings? *) Do we have a Polyakov-like formulation for branes as for strings, by introducing auxiliary fields? *) Where can I find a pedagogical treatment on the quantization of branes and the issues I mention here? The standard textbooks like Becker2Schwarz, Johnson etc. don't seem to answer my questions. Merry X-mas and all the best!