Lomonaco, Luciano A. On Singer’s algebra and coalgebra structures. (English) Zbl 1177.55010 Boll. Unione Mat. Ital., Sez. B, Artic. Ric. Mat. (8) 9, No. 3, 611-617 (2006). Summary: Recently W. M. Singer [Bull. Lond. Math. Soc. 37, No. 4, 627–635 (2005; Zbl 1080.55014)] has introduced the notion of algebra with coproducts (and the dual notion of coalgebra with products) somehow weakening the notion of Hopf algebra. In this paper we consider certain algebras of invariants and show that they are, in fact, further examples of algebras with coproducts and coalgebras with products. Moreover, we discuss the close relation between such algebras and the structures considered in Singer’s paper. Cited in 5 Documents MSC: 55S10 Steenrod algebra Citations:Zbl 1080.55014 PDFBibTeX XMLCite \textit{L. A. Lomonaco}, Boll. Unione Mat. Ital., Sez. B, Artic. Ric. Mat. (8) 9, No. 3, 611--617 (2006; Zbl 1177.55010)