Comments on: Norm of traceless Ricci tensor

Comments on: Norm of traceless Ricci tensor http://anhngq.wordpress.com/2011/05/30/norm-of-traceless-ricci-tensor/ Học học nữa học mãi Thu, 09 May 2013 22:44:49 +0000 hourly 1 http://wordpress.com/ By: Ngô Quốc Anh http://anhngq.wordpress.com/2011/05/30/norm-of-traceless-ricci-tensor/#comment-764 Wed, 01 Jun 2011 11:19:43 +0000 http://anhngq.wordpress.com/?p=6237#comment-764 Ah yes, that’s interesting. I was thinking in a traditional way, by calculus only. Thank you for your beautiful approach.

]]> By: K http://anhngq.wordpress.com/2011/05/30/norm-of-traceless-ricci-tensor/#comment-763 Wed, 01 Jun 2011 11:16:52 +0000 http://anhngq.wordpress.com/?p=6237#comment-763 I think a slightly tidier way to prove it, is to see that

$\displaystyle\mbox{Ric} -f g=\stackrel{\circ}{\mbox{Ric}}+(R/n-f)g$

and

$\displaystyle g\perp \stackrel{\circ}{\mbox{Ric}},$

so the identity follows from Pythagoras theorem.

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