Is superstringtheory a quantum theory ?

[vanesch]

A very naive question from a beginner:

I only know a very limited amount of string theory, and as far as I know it, it is a quantum theory in the strictest sense, namely that we still have a state in Hilbert space which evolves unitarily ; it is just the "theory to be quantized" that changes, from, say, QFT, into something vastly more complex (or simple, depends on the viewpoint :-). In fact, all I know about it is about the "theory to be quantized". Is this view, that superstring theory is a quantum theory, essentially correct, or am I completely off ?

cheers,
Patrick.

 

[selfAdjoint]

Given the amount of space the textbooks devote to different ways of quantizing it (canonical, light cone, etc. etc.) I would certainly say it is a quantum theory. Just as in other theories we often talk about the classical theory pre-quant, as in "wave function", yet those normal modes of the string are quantized (in simple cases quantum SHOs).

BTW it was Heisenberg, back in the late 1920s or early 1930s, who first quantized the string. It is one of the way stations on the road to QFT.

 

[vanesch]

Given the amount of space the textbooks devote to different ways of quantizing it (canonical, light cone, etc. etc.) I would certainly say it is a quantum theory. Just as in other theories we often talk about the classical theory pre-quant, as in "wave function", yet those normal modes of the string are quantized (in simple cases quantum SHOs).

That's what I also figured out, but it could be that I misunderstood it. The question is in fact if the "good old" strictly linear machinery of QM is used unaltered, with strictly unitary evolution and everything. I figured this was the case, but wanted to check.
The reason for my asking is more on the interpretational issue of QM. Some (Penrose) say that gravity might be a possible "solution" to the measurement problem in QM, but if superstrings is on the right track and if there is still our good old QM, then this option is out, I'd say.

cheers,
Patrick.

 

[Demystifier]

The reason for my asking is more on the interpretational issue of QM. Some (Penrose) say that gravity might be a possible "solution" to the measurement problem in QM, but if superstrings is on the right track and if there is still our good old QM, then this option is out, I'd say.

I would say that too. Nevertheless, string theory could solve the measurement problem in another way:
http://arxiv.org/abs/hep-th/0512186