On the integral Hodge conjecture for real varieties, I

Abstract

We formulate the "real integral Hodge conjecture", a version of the integral Hodge conjecture for real varieties, and raise the question of its validity for cycles of dimension 1 on uniruled and Calabi-Yau threefolds and on rationally connected varieties. We relate it to the problem of determining the image of the Borel-Haefliger cycle class map for 1-cycles, with the problem of deciding whether a real variety with no real point contains a curve of even geometric genus and with the problem of computing the torsion of the Chow group of 1-cycles of real threefolds. New results about these problems are obtained along the way.

67 pages; v2: minor modifications; v3: Section 1.1.3 slightly expanded, final version

References in corpus (2)

• Stably irrational hypersurfaces of small slopes
• On the integral Hodge conjecture for real varieties, II

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