In string theory, a worldsheet is a two-dimensional manifold which describes the embedding of a string in spacetime.[1] The term was coined by Leonard Susskind around 1967 as a direct generalization of the world line concept for a point particle in special and general relativity.

The type of string, the geometry of the spacetime in which it propagates, and the presence of long-range background fields (such as gauge fields) are encoded in a two-dimensional conformal field theory defined on the worldsheet. For example, the bosonic string in 26-dimensional Minkowski space[clarification needed] has a worldsheet conformal field theory consisting of 26 free scalar fields. Meanwhile, a superstring worldsheet theory in 10 dimensions consists of 10 free scalar fields and their fermionic superpartners.


  1. ^ Di Francesco, Philippe; Mathieu, Pierre; Sénéchal, David (1997). Conformal Field Theory. p. 8. doi:10.1007/978-1-4612-2256-9. ISBN 978-1-4612-2256-9.