The Euler characteristic for a Coxeter complex based on A_n goes like
chi = (-1)^n.2n.(n - 2)!!(n - 2)!!
which grows quickly but is only -6 for the case of A_3. Goodness me, that number does have a tendency to crop up, doesn't it now?
Tuesday, October 31, 2006
Mt Aspiring
Carl Brannen is currently enjoying Hawaii where he will be speaking about his derivation of the lepton masses. It is a large conference with a String theory session, which has some interesting sounding talks such as Sakurai on the geometric Langlands program. Amongst bloggers, at least Gordon Watts appears to be there. I guess we're heading into a busy conference season!
The Euler characteristic for a Coxeter complex based on A_n goes like
chi = (-1)^n.2n.(n - 2)!!(n - 2)!!
which grows quickly but is only -6 for the case of A_3. Goodness me, that number does have a tendency to crop up, doesn't it now?
The Euler characteristic for a Coxeter complex based on A_n goes like
chi = (-1)^n.2n.(n - 2)!!(n - 2)!!
which grows quickly but is only -6 for the case of A_3. Goodness me, that number does have a tendency to crop up, doesn't it now?
Kea, my sister is in academia, an English professor at Duchesne (Pittsburgh, Pennsylvania, USA).
ReplyDeleteHer son has dressed as, (well, see if you can guess without reading the story), for Halloween this year and she has put his photograph on her blog.
Hi Carl
ReplyDeleteObviously Neptune/Poseidon/Vishnu ?
Probably I'm leaving a couple of possibilities out!
Oh!! Perseus! My memory of these stories is often weak, I'm afraid, but I do like to read Greek works.
ReplyDeleteNo that's not right...oh, all right, tell me...
ReplyDeleteOh!! KALI. (I read the answer at last). But Kali is a woman!
ReplyDeleteI had fun at a fancy dress party last year. The theme was the letter P, so I went as Persephone, all ghoulish but covered in flowers. Everyone was very impressed that I had caught the bus to the party.
ReplyDelete