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We give three explicit finite-volume hyperbolic Coxeter lattices in dimension four whose adjoint trace fields are not totally real. They are the reflection groups of the Ma--Zheng polytopes P11,6, P11,7, P11,8. The obstruction is contained in two cyclic products of the doubled unit-normal Gram matrix $A=2G$. Those products recover elements s=√5 and u satisfying (s-1)u²+2(s-3)u+s-7=0. After the embedding s↦-√5, this quadratic has discriminant 8(1-√5)<0. The cyclic-product field therefore has a complex place. Vinberg's identification of that field with the adjoint trace field and the Emery--Mila total-reality obstruction imply that the three lattices are not pseudo-arithmetic. Torsion-free orientation-preserving finite-index subgroups yield orientable noncompact finite-volume hyperbolic $4$-manifolds with the same obstruction. Exact computations check the census data and provide independent field and finite-volume certificates. A pinned Lean~4 development verifies the radical identity and the number-field obstruction. It also checks the lattice and manifold implications conditional on explicit geometric and literature hypotheses.
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Alexander Kolpakov (2026) studied this question.
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