Massey products and relations in the cohomology of Steenrod algebras

In a recent paper Buchstaber and the author introduced a new structure on the cohomology of Hopf algebras in terms of the Buchstaber spectral sequence (Bss). We fully calculate this structure on the cohomology (known for a long time) of the important Hopf subalgebra A (1) of the classical Steenrod algebra A₂. As part of a demonstration of the methods of Bss, we solve the inverse problem and present a new explicit calculation of the s-dimensional cohomology of the algebra A (1) for s 4. We also use the methods of Bss to obtain results on the Massey products and relations in the cohomology of the Steenrod algebras Aₚ, p 2. Bibliography: 36 titles.