Norm-peak multilinear forms on l1

Abstract

Let n ∈ N, n≥ 2. A continuous n-linear form T on a Banach space E is called norm-peak if there is unique (x₁, . . . , x_n) ∈ En such that ∥x₁∥ = ··· = ∥x_n∥ = 1 and T attains its norm only at (±x₁,...,±x_n). In this paper, we characterize the norm-peak multilinear forms on l₁.