Title
Sylvester-Gallai type theorems for approximate collinearity
Abstract
We study questions in incidence geometry where the precise position of points is `blurry' (e.g. due to noise, inaccuracy or error). Thus lines are replaced by narrow tubes, and more generally affine subspaces are replaced by their small neighborhood. We show that the presence of a sufficiently large number of approximately collinear triples in a set of points in d dimensional complex space implies that the points are close to a low dimensional affine subspace. This can be viewed as a stable variant of the Sylvester-Gallai theorem and its extensions. Building on the recently found connection between Sylvester-Gallai type theorems and complex Locally Correctable Codes (LCCs), we define the new notion of stable LCCs, in which the (local) correction procedure can also handle small perturbations in the euclidean metric. We prove that such stable codes with constant query complexity do not exist. No impossibility results were known in any such local setting for more than 2 queries.
Year
Venue
DocType
2012
Electronic Colloquium on Computational Complexity (ECCC)
Journal
Volume
Citations 
PageRank 
abs/1211.0331
0
0.34
References 
Authors
8
4
Name
Order
Citations
PageRank
Albert Ai1451.89
Zeev Dvir243730.85
Shubhangi Saraf326324.55
Avi Wigderson482051064.31