worldsheets

This non-linear differential equation actually contains a lot of string theory information, and it is packaged in a way that is just the sort of thing we dream about in several other parts of string - (and M -) theory: It does not refer to strings by worldsheets, or any way that relies on thinking of the string as a string.

News From The Front, III cjohnson 2005

Conventional physics uses quadratic Lagrangians, two-dimensional worldsheets, second-rank tensors under Yang-Mills groups, commutators between two objects, and similar structures based on the number "2" all the time.

The Reference Frame 2010

(There is another motivation which you can forget about for the purposes of this discussion if you don’t know the language …. you can derive this model from an explicit realisation as a matrix model …. .from t’Hooft’s large N analysis, the matrix model 1/N expansion builds string worldsheets … turns out the parameter nu is sort of like a (renormalized) 1/N)

News From The Front, III cjohnson 2005