Subject: Re: 1-line From: Martin Benderksy Date: Wed, 02 Mar 2005 09:43:12 -0500 To: Don Davis Dear Don posting it sounds reasonable. here is the question: To prove Hopf invariant one for k=2^i one uses the fact that x2 = Sq^k(x) if |x|=k. Is there a similar formula in the Steenrod algebra, perhaps involving secondary operations that can be used to write x Sq1(x) (dim x = 2r)? --martin Don Davis wrote: > Dear Martin, > > I don't know the answer off the top of my head. You could try some examples. > Maybe you would like to post it? > > Don > > Martin Bendersky wrote: > >> Dear Don >> here is a question about the steenrod algebra. To prove Hopf Inv. one for n=2^i one uses the fact that x2 = Sq^k(x) if |x|=k. Is there a similar formual in the steenrod algebra that can be used to write x Sq1(x) (dim x = 2r)? >> >> --Martin >> >> >> On Tue, 01 Mar 2005 12:30:43 -0500, Don Davis wrote: >> >>> Dear Martin, >>> >>> I believe that the 1-line for SO(n) can be computed by exact sequences involving spheres and would turn out to >>> equal the v1-periodic 1-line. I haven't done this carefully, but expect it would be true. >>> >>> Don >> >> >> >> > >