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arXiv · 2001.10962

Harmonic Forms on the Kodaira-Thurston Manifold

Tom Holt·Weiyi Zhang
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Abstract

We introduce an effective method to solve the $\bar\partial$-harmonic forms on the Kodaira-Thurston manifold endowed with an almost complex structure and an Hermitian metric. Using the Weil-Brezin transform, we reduce the elliptic PDE system to countably many linear ODE systems. By solving a fundamental problem on linear ODE systems, the problem of finding $\bar\partial$-harmonic forms is equivalent to a generalised Gauss circle problem. We demonstrate two remarkable applications. First, the dimension of the almost complex $\bar\partial$-Hodge numbers on the Kodaira-Thurston manifold could be arbitrarily large. Second, Hodge numbers vary with different choices of Hermitian metrics. This answers a question of Kodaira and Spencer in Hirzebruch's 1954 problem list.

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Tom Holt, Weiyi Zhang. 2020-01-29. Harmonic Forms on the Kodaira-Thurston Manifold. https://arxiv.org/abs/2001.10962

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