Hodge conjecture for projective hypersurface
Johann Bouali
TL;DR
This work develops the theory of complex analytic logarithmic De Rham classes and exploits a motivic purity framework to connect analytic $(d,d)$-classes with algebraic cycles. For smooth hypersurfaces $X$ with odd ambient dimension, the authors show that any Hodge class $\lambda\in F^pH^{2p}(X^{an},\mathbb Q)$ arises from an algebraic cycle, by expressing $\lambda$ via a residue from the hypersurface complement and using log De Rham tools to descend to a cycle on $X$. The approach unifies analytic and algebraic perspectives through period maps, residue morphisms, and transfers in the motivic setting, culminating in a full Hodge conjecture result for hypersurfaces. Overall, the paper extends known cases of the Hodge conjecture to broad classes of hypersurfaces and introduces analytic logarithmic De Rham classes as a key bridge between analysis and algebraic geometry.
Abstract
We show that a Hodge class of a complex smooth projective hypersurface is an analytic logarithmic De Rham class. On the other hand we show that for a complex smooth projective variety an analytic logarithmic De Rham class of of type $(d,d)$ is the class of codimension $d$ algebraic cycle. We deduce the Hodge conjecture for smooth projective hypersurfaces.
