A characterization of Banach spaces containing ℓ1(κ) via ball-covering properties

S Ciaci, J Langemets, A Lissitsin - Israel Journal of Mathematics, 2023 - Springer
In 1989, G. Godefroy proved that a Banach space contains an isomorphic copy of ℓ1 if and
only if it can be equivalently renormed to be octahedral. It is known that octahedral norms …

Attaining strong diameter two property for infinite cardinals

S Ciaci, J Langemets, A Lissitsin - Journal of Mathematical Analysis and …, 2022 - Elsevier
We extend the (attaining of) strong diameter two property to infinite cardinals. In particular, a
Banach space has the 1-norming attaining strong diameter two property with respect to ω (1 …

Slicely countably determined points in Banach spaces

J Langemets, M Lõo, M Martin, AR Zoca - Journal of Mathematical Analysis …, 2024 - Elsevier
We introduce slicely countably determined points (SCD points) of a bounded and convex
subset of a Banach space which extends the notions of denting points, strongly regular …

A RENORMING CHARACTERISATION OF BANACH SPACES CONTAINING

A Avilés, G Martínez-Cervantes… - Publicacions …, 2023 - projecteuclid.org
A result of G. Godefroy asserts that a Banach space X contains an isomorphic copy of ℓ 1 if
and only if there is an equivalent norm|||·||| such that, for every finite-dimensional subspace Y …

On norm derivatives and the ball-covering property of Banach spaces

D Sain - Journal of Mathematical Analysis and Applications, 2025 - Elsevier
We study a local version of the ball-covering problem in Banach spaces, and obtain a
complete solution to it in terms of the norm derivatives. We illustrate the advantage of the …

A renorming Characterisation of Banach Spaces containing ℓ 1 (κ)

AD Avilés Redondo, G Martínez Cervantes… - 2023 - digibug.ugr.es
A result of G. Godefroy asserts that a Banach space X contains an isomorphic copy of ℓ 1 if
and only if there is an equivalent norm|||⋅||| such that, for every finite-dimensional subspace …