We give the simplest known algebraic proof of the PCP theorem, involving only ingredients like code concatenation, polynomial interpolation, and polynomial multiplication. Specifically, we prove that graph 3-coloring has a polynomial-sized proof that can be verified by a verifier tossing logarithmically many coins and querying a constant number of bits ... more >>>

Given two symbolic matrices $X$ and $Y$ of dimensions $m\times n$ and $n\times m$, respectively, the *rank principle* states that when $m = n+1$ and $A$ is a scalar matrix of rank $n+1$, the equation $XY = A$ is unsatisfiable. When $m$ is arbitrarily larger than $n$ and $A$ has ... more >>>

We extend the recent work of Reis and Rothvoss on sparsifying sums of $\ell_1$ norms to the more general task of sparsifying (Minkowski) sums of centrally symmetric, convex sets. As our main result, we prove that for any $\varepsilon > 0$ and centrally symmetric, convex sets $C_1, \ldots, C_m\subseteq\mathbb R^n$ ... more >>>