This is an announcement for the paper "Stability of vector measures and twisted sums of Banach spaces" by Tomasz Kochanek.
Abstract: A Banach space $X$ is said to have the $\mathsf{SVM}$ (stability of vector measures) property if there exists a~constant $v<\infty$ such that for any algebra of sets $\mathcal F$, and any function $\nu\colon\mathcal F\to X$ satisfying $$|\nu(A\cup B)-\nu(A)-\nu(B)|\leq 1\quad\mbox{for disjoint }A,B\in\mathcal F,$$there is a~vector measure $\mu\colon\mathcal F\to X$ with $|\nu(A)-\mu(A)|\leq v$ for all $A\in\mathcal F$. If this condition is valid when restricted to set algebras $\mathcal F$ of cardinality less than some fixed cardinal number $\kappa$, then we say that $X$ has the $\kappa$-$\mathsf{SVM}$ property. The least cardinal $\kappa$ for which $X$ does not have the $\kappa$-$\mathsf{SVM}$ property (if it exists) is called the $\mathsf{SVM}$ character of $X$. We apply the machinery of twisted sums and quasi-linear maps to characterise these properties and to determine $\mathsf{SVM}$ characters for many classical Banach spaces. We also discuss connections between the $\kappa$-$\mathsf{SVM}$ property, $\kappa$-injectivity and the `three-space' problem.
Archive classification: math.FA
Mathematics Subject Classification: Primary 28B05, 46G10, 46B25, Secondary 46B03
Submitted from: t.kania@lancaster.ac.uk
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1208.4755
or