SLIDE 43 Popa’s symmetric enveloping algebra
Theorem (Popa ’94)
Let N ⊂ M be an inclusion of II1 factors with [M : N] < ∞. Then there is a (unique up to conjugacy) II1 factor M ⊠eN Mop such that:
1 There is an anti-automorphism x → xop of M ⊠eN Mop such that
(xop)op = x.
2 There is an inclusion M ⊗ Mop ֒
→ M ⊠eN Mop such that (x ⊗ yop)op = y ⊗ xop.
3 There is a projection eN ∈ M ⊠eN Mop such that eop
N = eN, and eN is
the Jones projection for the inclusions N ⊂ M and Nop ⊂ Mop.
4 M ⊠eN M is generated by M ⊗ Mop and eN.
M amenable, N ⊂ M finite-depth ⇒ M ⊗ Mop ⊂ M ⊠eN Mop ≃ Ocneanu’s asymptotic inclusion. Index = I, related to Drinfeld double.
Stephen Curran (UCLA) Symmetric enveloping algebra May 26, 2011 9 / 16