Sequential continuity and submeasurable cardinals

Submeasurable cardinals are defined in a similar way as measurable cardinals are. Their characterizations are given by means of sequentially continuous pseudonorms (or homomorphisms) on topological groups and of sequentially continuous (or uniformly continuous) functions on Cantor spaces (for that purpose it is proved that if a complete Boolean algebra admits a nonconstant sequentially continuous function, it admits a Maharam submeasure).