DJAIDJA, KHOULOUD2020-10-252020-10-252020https://repository.univ-msila.dz/handle/123456789/20045In the theory of s-numbers, on associates with every bounded linear operator T from a Banach space X into a Banach space Y various kinds of scalar sequences kTk = s1(T) ≥ s2(T) ≥...≥ 0. In this memory we present an axiomatic theory of s-numbers and we discuss related operator ideals obtained in this way.enFinite rank operator, s-number, Operator ideal, Entropy number.Thesis