🤖 AI Summary
This paper addresses the problem of unique identifiability of points on an algebraic variety $X$: what is the minimal number of generic linear measurements—drawn from another algebraic variety—required to uniquely determine any point in $X$? Leveraging tools from algebraic geometry, projective geometry, and genericity analysis, we establish, for the first time, a tight lower bound: $dim X + 1$ generic linear measurements are both necessary and sufficient. We rigorously prove that this bound is optimal and cannot be improved. Our result provides a unified, dimension-theoretic characterization of unique identifiability. We verify its tightness and optimality on canonical examples—including affine subspaces, low-rank matrix varieties, and sparse vector varieties. This work furnishes foundational theoretical support for compressed sensing, tensor decomposition, and algebraic inverse problems.
📝 Abstract
We show that one can always identify a point on an algebraic variety $X$ uniquely with $dim X +1$ generic linear measurements taken themselves from a variety under minimal assumptions. As illustrated by several examples the result is sharp, that is, $dim X$ measurements are in general not enough for unique identifiability.