A remark on secondary cohomology operations

A remark on the rational cohomology of S1,n

We focus on the rational cohomology of Cornalba’s moduli space of spin curves of genus 1 with n marked points. In particular, we show that both its first and its third cohomology group vanish and the second cohomology group is generated by boundary classes.

The Factorization of Cyclic Reduced Powers by Secondary Cohomology Operations.

I Lewin, J. C., Science, 112, 652 (1950). 2 In the experiments reported here, cultures were grown on minimal medium plus sodium acetate (0.2 gm per 100 ml). The minimal medium, described in Levine, R. P., and Ebersold, W. T., Zeit. Vererbungs., 89, 632 (1958), was altered by a fivefold increase in the concentration of Beijerinck's solution. 3 Arnon, D. I., Plant Physiol., 24, 1 (1949). 4The aut...

Secondary Steenrod Operations in Cohomology of Infinite-Dimensional Projective Spaces

The important role of the Steenrod operations Sq in the description of the cohomology of topological spaces, the calculation of various spectral sequences, and the study of homotopy properties of topological spaces and their continuous maps is well known [1, 2]. Projective spaces, in particular RP∞ and CP∞ , play a special role in the construction of Steenrod operations and their computation. I...

On the Steenrod Operations in Cyclic Cohomology

For a commutative Hopf algebra A over Z/p, where p is a prime integer, we define the Steenrod operations P i in cyclic cohomology of A using a tensor product of a free resolution of the symmetric group S n and the standard resolution of the algebra A over the cyclic category according to Loday (1992). We also compute some of these operations. 1. Introduction. For any prime p, the mod p Steenrod...

A Remark on a Remark by Macaulay or Enhancing Lazard Structural Theorem