Additional Symmetries and String Equation of the CKP Hierarchy.

Based on the Orlov and Shulman’s M operator, the additional symmetries and the string equation of the CKP hierarchy are established, and then the higher order constraints on L ^l are obtained. In addition, the generating function and some properties are also given. In particular, the additional symmetry flows form a new infinite dimensional algebra $$W^C_{1+\infty}$$ , which is a subalgebra of W _1+∞. [ABSTRACT FROM AUTHOR]