13,249 research outputs found
Apparent contours of nonsingular real cubic surfaces
We give a complete deformation classification of real Zariski sextics, that
is of generic apparent contours of nonsingular real cubic surfaces. As a
by-product, we observe a certain "reversion" duality in the set of deformation
classes of these sextics.Comment: 61 pages, 8 figures, Revised version to be published in Transactions
AMS: some minor corrections, a missing lemma is include
Surfaces with triple points
In this paper we compute upper bounds for the number of ordinary triple
points on a hypersurface in and give a complete classification for degree
six (degree four or less is trivial, and five is elementary). But the real
purpose is to point out the intricate geometry of examples with many triple
points, and how it fits with the general classification of surfaces
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