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Apr 13, 2017 at 12:57 history edited CommunityBot
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Dec 14, 2009 at 15:38 vote accept Jean Delinez
Dec 11, 2009 at 19:45 comment added José Figueroa-O'Farrill I've now taken the liberty to edit the question to show the right groups.
Dec 11, 2009 at 19:45 history edited José Figueroa-O'Farrill CC BY-SA 2.5
Reindexed the groups correctly.
Dec 11, 2009 at 18:50 comment added José Figueroa-O'Farrill Yes, but you've relabeled the wrong way. $\mathbb{CP}^n = SU(n+1)/U(n)$ in your notation. Notice that the action of $SU(n+1)$ is basically the linear action on $\mathbb{C}^{n+1}$, thought of as the fundamental representation. Think about the case $n=1$: $\mathbb{CP}^1$ is the 2-sphere acted on by $SU(2)$.
Dec 11, 2009 at 18:23 history edited Jean Delinez CC BY-SA 2.5
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Dec 11, 2009 at 18:21 comment added Jean Delinez Yes, of course.
Dec 11, 2009 at 18:01 comment added José Figueroa-O'Farrill I just noticed that what you have defined is $\mathbb{CP}^{n-1}$. I think that it's best to leave that as $\mathbb{CP}^n$ and relabel the groups. So your question is about $U(n)$.
Dec 11, 2009 at 17:51 history edited Jean Delinez CC BY-SA 2.5
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Dec 11, 2009 at 17:50 comment added Jean Delinez yes, that's what I mean. It came from my supervisor who is pretty heavily physics influenced.
Dec 11, 2009 at 17:15 answer added David E Speyer timeline score: 4
Dec 11, 2009 at 16:47 comment added David E Speyer I think you are right. (And some googling of the physics literature agrees with you). I think I am also right. See my longer answer below.
Dec 11, 2009 at 16:32 comment added José Figueroa-O'Farrill I think that holomorphic and antiholomorphic refer, respectively, to (1,0) and (0,1) forms. This is a typical notation in the Physics literature, at least.
Dec 11, 2009 at 13:15 comment added David E Speyer Holomorphic forms appears to mean holomorphic 1-forms. At least, that's how Jean Delinez seemed to use this terminology in his previous question. mathoverflow.net/questions/8282/… It also seems that "antiholomorphic forms" is the dual vector bundle to "holomorphic forms", that is to say, it is the holomorphic tangent bundle. I find this terminology very strange, so I worry that I am misunderstanding it. If anyone has run across this terminology before, please leave a helpful comment.
Dec 11, 2009 at 9:47 comment added José Figueroa-O'Farrill I think that there might be some ambiguity in the notation in the original version of the question and this might be causing some consusion below. (I would edit, but I'm not sure if this is OK.) The projective space is $U(n)/(U(n-1) \times U(1))$ or, if you prefer to have $SU(n)$ on the top, $SU(n)/(S(U(n-1)\times U(1))$. The subgroup in the denominator consists of block diagonal $U(n)$ matrices of the form $(g,1/\det g)$, where $g$ is unitary of size $n-1$ embedded in $U(n)$ in the obvioua way. This specifies the $U(n-1)$ subgroup -- up to conjugation, of course.
Dec 11, 2009 at 7:11 answer added David Bar Moshe timeline score: 3
Dec 11, 2009 at 1:58 comment added Kevin H. Lin For the second question, the first paragraph of the section "Formulation" on this wikipedia page en.wikipedia.org/wiki/Borel%E2%80%93Weil%E2%80%93Bott_theorem might help?
Dec 11, 2009 at 0:20 comment added Kevin H. Lin What is meant by "bundle of holomorphic forms" and "bundle of antiholomorphic forms"?
Dec 11, 2009 at 0:20 history edited Kevin H. Lin CC BY-SA 2.5
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Dec 10, 2009 at 22:43 history edited Kevin H. Lin
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Dec 10, 2009 at 21:36 history edited Jean Delinez CC BY-SA 2.5
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Dec 10, 2009 at 21:15 history edited Jean Delinez CC BY-SA 2.5
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Dec 10, 2009 at 21:08 history asked Jean Delinez CC BY-SA 2.5