Posted: **Sep 03, 2010 6:56 am**

by **newolder**

Preno wrote:newolder wrote:My understanding is that all (mathematical) groups are embedded in E8

No.

I've failed at rigour again.

I meant the Lie groups.

My understanding of Calabi-Yau is that the manifold structure (e.g. the number of holes it has) depends on the dimension count

I'm not sure what this is supposed to mean,

http://library.thinkquest.org/27930/stringtheory5.htm wrote:... The first step toward such a goal has been taken in the realization that Calabi-Yau spaces contain holes of various numbers of dimensions which can affect a string's vibrational pattern. This goes a long way toward answering one of particle physics' most intriguing questions: why are there three families of elementary particles? why not one, or four, or any other number? The answer proposed by string theory is as follows...

but at any rate dimensionality is a property of any manifold.

I'm sure it is.