Log weak Lefschetz conjecture for log isocrystalline cohomologies

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Let YY be a projective SNCL scheme over the log point ss, let EE be a horizontal smooth divisor on YY, and let d=dim⁡Yd=\dim Y. Let qq be a nonnegative integer. Write K0=Frac⁡(W)K_0=\operatorname{Frac}(\mathcal W) and, for a W\mathcal W-module MM, write MK0=M⊗WK0M_{K_0}=M\otimes_{\mathcal W}K_0. The closed immersion ι ⁣:E↪Y\iota\colon E\hookrightarrow Y induces

ιcrys∗ ⁣:Hcrysq(Y/W(s))K0⟶Hcrysq(E/W(s))K0.\iota^*_{\rm crys}\colon H^q_{\rm crys}(Y/\mathcal W(s))_{K_0}\longrightarrow H^q_{\rm crys}(E/\mathcal W(s))_{K_0}.

The cohomology groups carry weight filtrations PP.

Log weak Lefschetz conjecture. Assume that OY(E)\mathcal O_Y(E) is ample. Then the morphism above is a filtered isomorphism with respect to PP if q≤d−2q\leq d-2 and strictly injective for q=d−1q=d-1.

This is a logarithmic analogue of the weak Lefschetz theorem for log crystalline cohomology. The source introduces it as a conjecture and gives an affirmative result, but the supplied text does not specify whether the full conjecture is resolved.

References

Primary source

Yukiyoshi Nakkajima and Fuetaro Yobuko, “Degenerations of log Hodge de Rham spectral sequences, log Kodaira vanishing theorem in characteristic p>0 and log weak Lefschetz conjecture for log crystalline cohomologies”, arXiv:1902.09110 (2022).

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