Real Forms
There are 3 simple real Lie algebras associated with this root system:
- The underlying real Lie algebra of the complex Lie algebra G2 has dimension 28. It has complex conjugation as an outer automorphism and is simply connected. The maximal compact subgroup of its associated group is the compact form of G2.
- The Lie algebra of the compact form is 14 dimensional. The associated Lie group has no outer automorphisms, no center, and is simply connected and compact.
- The Lie algebra of the non-compact (split) form has dimension 14. The associated simple Lie group has fundamental group of order 2 and its outer automorphism group is the trivial group. Its maximal compact subgroup is SU(2) × SU(2)/(−1,−1). It has a non-algebraic double cover that is simply connected.
Read more about this topic: G2 (mathematics)
Famous quotes containing the words real and/or forms:
“When I read of the vain discussions of the present day about the Virgin Birth and other old dogmas which belong to the past, I feel how great the need is still of a real interest in the religion which builds up character, teaches brotherly love, and opens up to the seeker such a world of usefulness and the beauty of holiness.”
—Olympia Brown (1835–1900)
“Ring out a slowly dying cause,
And ancient forms of party strife;
Ring in the nobler modes of life,
With sweeter manners, purer laws.”
—Alfred Tennyson (1809–1892)