Parameter Rays For The Cosine Family

In this paper, it is mainly discussed the set (?) of parameters k∈C for which the critical orbit of E_k(z)=e^k(e^z+e^-z) escapes to oo. These parameters will be called 'escaping parameters', and be organized in the form of rays which are called parameter rays. Every escaping parameter can be connected to oo along a unique curve running entirely along escaping parameter, and every point in parameter ray is escaping parameter...