The λ-function in -triples

We discuss the λ-function in the general setting of J B ⁎ -triples. Several results connecting the λ-function with the distance of a vector to the Brown–Pedersenʹs quasi-invertible elements and extreme convex decompositions have been obtained for J B ⁎ -triples; these include J B ⁎ -triple analogues of some related C ⁎ -algebra results due to M. Rørdam, L. Brown and G. Pedersen.