Talk:G2 (mathematics)

Should we move G2 to G2(math)? Someone just claimed G2 is also the name of an Apple release. Phys

To ease uniformization, I'll move this to G2 (mathematics) Phys

G2 is the name of a Peer to Peer Network... --Nate3000 08:28, 1 Jun 2005 (UTC)

Ambiguity for new learners[edit]

This page refers to G2 in both plural and singular mode:

Here the plural is used:

G2 is the name of some Lie groups and also their Lie algebras . They are the smallest of the five exceptional simple Lie groups.

The very next sentence uses singular.

Is there only one G2 group (up to isomorphism) or are there many?

67.190.17.110 13:55, 15 February 2007 (UTC) BL[reply]

Well the language could certainly be cleaned up. There are many things called G₂ but usually only one thing (up to isomorphism) of any given type:

There is one root system called G₂.
There is one complex Lie algebra called G₂.
There is one complex Lie group called G₂.
There are two real Lie algebras called G₂, although usually the compact form is meant.
There are two real Lie groups called G₂, but again one almost always means the compact one.

-- Fropuff 18:48, 15 February 2007 (UTC)[reply]

Possible Typo in the Section 'Algebra'?[edit]

The arrow in the Dynkin diagram should be facing left, since in the text below root 1 is short and root 2 is long — Preceding unsigned comment added by 144.32.240.72 (talk) 10:59, 17 February 2017 (UTC)[reply]

Possible Typo in the Section 'Real Forms'?[edit]

Lie algebra aren't my specialism but I know enough to know that

Its maximal compact subgroup is SU(2) × SU(2)/(−1,−1)

looks a bit suspect. Should it perhaps be "SU(2) × SU(2)/(1,−1)", as in the quotient group taken with Z₂? PanDTV (talk) 04:21, 6 June 2015 (UTC)[reply]