Ramified Quadrangles of Type E6, E7 and E8
This chapter deals with the case that the building at infinity of the Bruhat-Tits building Ξ is a Moufang ramified quadrangle of type E⁶, E₇ and E₈. The basic proposition is that Ξ is a ramified quadrangle if δΛ = δΨ = 1 holds. The chapter proves the theorem that if δΨ = 1 and the Moufang residues R₀ and R₁ are not both indifferent, there exists an involutory set. It also discusses the cases ℓ = 6, ℓ = 7, and ℓ = 8, in which D is a quaternion division algebra.
2009 ◽
Vol 61
(6)
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pp. 1325-1340
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1981 ◽
Vol 33
(6)
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pp. 1370-1379
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