Department of Pure Mathematics, the University of Sheffield.
This was a working meeting with the usual time for participant discussion.
2 February 2010
In joint work with Niles Johnson, we have computed some obstructions for an H_\infty complex orientation to factor through the Brown-Peterson spectrum. The non-triviality of these obstructions show that a number of standard ring spectra maps MU-->E, can not be maps of E_\infty ring spectra. Examples include E=BP, E_n, and E(n) for n>0 and p<7.
The meeting was partially supported by a Scheme 3 grant from the London Mathematical Society.