1
vote
1answer
35 views

If QFT is a sum over 1-D topologies and String Theory over 2-D topologies, what is the corresponding theory for N-D topologies?

My understanding is that perturbative QFT can essentially be described as a weighted sum over 1-D topologies (ie Feynman graphs), and String theory is essentially the generalization to a sum over 2-D ...
0
votes
1answer
205 views

Does string/M-theory address higher-dimensional membrane vibration modes?

A loop is a 1-sphere that can vibrate in increasingly complex ways as it is embedded in higher dimensional spaces. Does string theory assume that 1-spheres are the only possible vibrating ...
2
votes
0answers
209 views

Tree level and loop level

I'm trying to read through a paper which explains the following about Universal Extra Dimensions (UED) vs ADD models: The new feature of the UED scenario compared to the brane world is that ...
3
votes
2answers
316 views

String theory: why not use $n$-dimensional blocks/objects/branes?

I have a basic question: if we use 1d string to replace 0d particle to gain insight of nature in string theory, and advanced to use 2d membranes, can we imagine that using $3$- or $n$-dimensional ...
6
votes
1answer
165 views

Critical dimension in quantization of p-branes

So I have what might be a fairly basic question, but my understanding that in the quantization of the the string, or the 1-brane, there are conditions on the number of spacetime dimensions to ensure ...
12
votes
2answers
658 views

Why one-dimensional strings, but not higher-dimensional shells/membranes?

One way that I've seen to sort-of motivate string theory is to 'generalize' the relativistic point particle action, resulting in the Nambu-Goto action. However, once you see how to make this ...