3 papers
math.FA2019
On the ${\Ext}^2$-problem for Hilbert spaces
Félix Cabello Sánchez, Jesús M. F. Castillo, Willian H. G. Corrêa +2
We show that $\Ext^2(\ell_2, \ell_2)\neq 0$ in the category of Banach spaces. This solves a sharpened version of Palamodov's problem and provides a solution to the second order ver…
math.FA2019
Complex interpolation of families of Orlicz sequence spaces
Willian Hans Goes Corrêa
We study the complex interpolation and derivation process induced by a family of Orlicz sequence spaces. We present a concrete example of interpolation family of three spaces induc…
math.FA2017
Type, cotype and twisted sums induced by complex interpolation
Willian Hans Goes Corrêa
This paper deals with extensions or twisted sums of Banach spaces that come induced by complex interpolation and the relation between the type and cotype of the spaces in the inter…