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arXiv · 1002.2209

Linear forms and quadratic uniformity for functions on $\mathbb{F}_p^n$

W. T. Gowers·J. Wolf
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Abstract

We give improved bounds for our theorem in [GW09], which shows that a system of linear forms on $\mathbb{F}_p^n$ with squares that are linearly independent has the expected number of solutions in any linearly uniform subset of $\mathbb{F}_p^n$. While in [GW09] the dependence between the uniformity of the set and the resulting error in the average over the linear system was of tower type, we now obtain a doubly exponential relation between the two parameters. Instead of the structure theorem for bounded functions due to Green and Tao [GrT08], we use the Hahn-Banach theorem to decompose the function into a quadratically structured plus a quadratically uniform part. This new decomposition makes more efficient use of the $U^3$ inverse theorem [GrT08].

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W. T. Gowers, J. Wolf. 2010-02-10. Linear forms and quadratic uniformity for functions on $\mathbb{F}_p^n$. https://doi.org/10.1112/s0025579311001264

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