P-Tensor Product for Group C-Algebras

• Published in: Mathematics (Basel) Vol. 8; no. 4; p. 627
• Main Authors: Li, Yufang, Dong, Zhe
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.04.2020
• Subjects: 2000 MR Subject Classification; amenability; Haagerup property; p-tensor product; Primary20F65
• ISSN: 2227-7390; 2227-7390
• DOI: 10.3390/math8040627

In this paper, we introduce new tensor products ⊗ p ( 1 ≤ p ≤ + ∞ ) on C ℓ p * ( Γ ) ⊗ C ℓ p * ( Γ ) and ⊗ c 0 on C c 0 * ( Γ ) ⊗ C c 0 * ( Γ ) for any discrete group Γ . We obtain that for 1 ≤ p < + ∞ C ℓ p * ( Γ ) ⊗ m a x C ℓ p * ( Γ ) = C ℓ p * ( Γ ) ⊗ p C ℓ p * ( Γ ) if and only if Γ is amenable; C c 0 * ( Γ ) ⊗ m a x C c 0 * ( Γ ) = C c 0 * ( Γ ) ⊗ c 0 C c 0 * ( Γ ) if and only if Γ has Haagerup property. In particular, for the free group with two generators F 2 we show that C ℓ p * ( F 2 ) ⊗ p C ℓ p * ( F 2 ) ≇ C ℓ q * ( F 2 ) ⊗ q C ℓ q * ( F 2 ) for 2 ≤ q < p ≤ + ∞ .