of a single string state is described as a long cylinder, states in the Neveu–Schwarz sector are anti-periodic and states in the Ramond sector are periodic. In the z-frame, in which the worldsheet of a single string state is described as an infinite punctured plane, the opposite is true. The Neveu–Schwarz sector and Ramond sector are also defined in the open string and depend on the boundary conditions of the fermionic field at the edges of the open string. See also N = 2 superconformal algebra NS–NS sector Ramond–Ramond sector Superconformal algebra Notes References Theoretical physics String theory Lie algebras Conformal field theory Boundary conditions