Conditional quasi-greedy bases in non-superreflexive Banach spaces

Fernando Albiac, José L. Ansorena, Przemysław Wojtaszczyk

For a conditional quasi-greedy basis $\mathcal{B}$ in a Banach space the associated conditionality constants $k_m[\mathcal{B}]$ verify the estimate $k_{m}[\mathcal{B}]=\mathcal{O…