Weak weight-semi-greedy Markushevich bases

Abstract

We introduce and study the notion of weak weight-semi-greedy Markushevich bases - which extends the concepts of weight semi-greedy and weak semi-greedy Markushevich bases. In particular, we study conditions under which such bases are weight almost greedy. We also define the notion of weak weight almost greedy bases, and prove that this formally weaker concept is equivalent to that concept of weight almost greedy bases. Finally, we study some parameters involving the weak thresholding and Chebyshevian greedy algorithms.