On the $ K $ -functionals of Absolutely Calderón Elements of the Banach Pair $ (l_{1},c_{0}) $

Abstract

We characterize the absolutely Calderón elements of the canonical pair \( (l_{1},c_{0}) \) of sequence spaces in terms of the Peetre \( K \)-functional. This result has been known to the first author since rather long ago but the proof appears here. Also, we formulate a few unsolved problems.