Year: 2026
Type: article
Abstract: How reasonable is the conjecture that $$\ell _\infty /C[0,1]$$ ℓ ∞ / C [ 0 , 1 ] separably injective? Formulated in homological terms this amounts to asking whether $$\operatorname {Ext}^2(S, C[0,1])=0$$ Ext 2 ( S , C [ 0 , 1 ] ) = 0 for every separable space. We wheel around this question and obtain new connections between $$\operatorname {Ext}^2$$ Ext 2 -results and classical Banach space theorems of Johnson–Zippin, Kalton and Lindenstrauss–Pełczyński.
Authors: Jesús M. F. Castillo, Yolanda Moreno
Institution: Universidad de Extremadura
Language: English
Topic: Advanced Banach Space Theory
Subfield: Mathematical Physics
Field: Mathematics
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,390
OpenAlex ID: W7142644358