After describing the origins of the subject in the study of summability of series, it presents the general theory for tauberian operators on abstract Banach spaces.    From Wordnik.com.  [AvaxHome RSS:] Reference

The image V of this isometry is the smallest closed subspace of H that contains Note the contrast here between conditional and unconditional summability (which needs only square-summability of the coefficients are absolutely summable).    From Wordnik.com.  [What's new] Reference

39-XX Difference and functional equations summability.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

40Dxx Direct theorems on summability.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

40F05 Absolute and strong summability.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

40H05 Functional analytic methods in summability.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference