most recent 30 from http://mathoverflow.net 2013-05-24T00:51:32Z http://mathoverflow.net/feeds/user/2292 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/7715/what-is-restriction-of-scalars-for-a-torus peter-struwwel 2009-12-03T20:55:31Z 2010-01-15T19:45:42Z

<p>I am starting on a Phd program and am supposed to read Colliot Thelene and Sansuc's article on R-equivalence for tori. I find it very difficult and although I have some knowledge over schemes , I am completely baffled by this scalar restriction business of having a field extension $K/k$ , a torus over $K$ and "restricting" it to $k$. I would be very gratefull for a reference or even better by some explanation . I found nothing in my standard books (Hartshorne, Qing Liu, Mumford etc) so I hope this question is appropriate for the site. Thank you.</p>

http://mathoverflow.net/questions/7715/what-is-restriction-of-scalars-for-a-torus/7755#7755 2009-12-05T21:36:53Z 2009-12-05T21:36:53Z

Giving the points over one field of a torus doesn't even begin to describe it. the comment &quot;it's not hard at all&quot; is useless and patronising.

http://mathoverflow.net/questions/7715/what-is-restriction-of-scalars-for-a-torus/7765#7765 2009-12-04T21:41:24Z 2009-12-04T21:41:24Z

Thanks for this long answer and the link to your notes.