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arXiv · 2301.09929

$q$-bic forms

Raymond Cheng
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Abstract

A $q$-bic form is a pairing $V \times V \to \mathbf{k}$ that is linear in the second variable and $q$-power Frobenius linear in the first; here, $V$ is a vector space over a field $\mathbf{k}$ containing the finite field on $q^2$ elements. This article develops a geometric theory of $q$-bic forms in the spirit of that of bilinear forms. I find two filtrations intrinsically attached to a $q$-bic form, with which I define a series of numerical invariants. These are used to classify, study automorphism group schemes of, and describe specialization relations in the parameter space of $q$-bic forms.

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Raymond Cheng. 2023-01-24. $q$-bic forms. https://doi.org/10.1016/j.jalgebra.2025.03.031

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