FIXED POINTS SUBGROUPS G^{σ, σ′} BY TWO INVOLUTIVE AUTOMORPHISMS σ, σ′ OF EXCEPTIONAL COMPACT LIE GROUP G. PART II: G = E₈

抄録

For the simply connected compact exceptional Lie group E₈, we determine the structure of subgroup (E₈)^σ,σ′ of E₈ that is the intersection (E₈)^σ ∩ (E₈)^σ′ . Then the space E₈/(E₈)^σ,σ′ is the exceptional Z₂ × Z_2- symmetric space of type EVIII-VIII-VIII, and we give two involutions σ, σ′ for the space E₈/(E₈)^σ,σ′ concretely.