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arXiv · 1404.1641

Exterior splashes and linear sets of rank 3

S. G. Barwick·Wen-Ai Jackson
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Abstract

In $\PG(2,q^3)$, let $\pi$ be a subplane of order $q$ that is exterior to $\li$. The exterior splash of $\pi$ is defined to be the set of $q^2+q+1$ points on $\li$ that lie on a line of $\pi$. This article investigates properties of an exterior \orsp\ and its exterior splash. We show that the following objects are projectively equivalent: exterior splashes, covers of the circle geometry $CG(3,q)$, Sherk surfaces of size $q^2+q+1$, and $\GF(q)$-linear sets of rank 3 and size $q^2+q+1$. We compare our construction of exterior splashes with the projection construction of a linear set. We give a geometric construction of the two different families of sublines in an exterior splash, and compare them to the known families of sublines in a scattered linear set of rank 3.

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S. G. Barwick, Wen-Ai Jackson. 2014-04-07. Exterior splashes and linear sets of rank 3. https://arxiv.org/abs/1404.1641

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