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Decomposition theorem for the cd-index of Gorenstein* posets

Richard Ehrenborg·Kalle Karu
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Abstract

We prove a decomposition theorem for the cd-index of a Gorenstein* poset analogous to the decomposition theorem for the intersection cohomology of a toric variety. From this we settle a conjecture of Stanley that the cd-index of Gorenstein* lattices is minimized on Boolean algebras.

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Richard Ehrenborg, Kalle Karu. 2006-11-14. Decomposition theorem for the cd-index of Gorenstein* posets. https://arxiv.org/abs/math/0611440

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