Some analogies between the c-numerical range and a certain variation on this concept
The parallelism between the sets \(W_ c(A)\) and \(\Delta_ c(A)\) is further studied [cf. the author's paper in Port. Math. 43 (1985/86), 189- 200 (1986; reviewed above)]. One of the analogies is an elliptic range theorem.
scientific article; zbMATH DE number 3991708