Computer Science and Discrete Mathematics (CSDM)

Choiceless Polynomial Time

Ben Rossman

The choiceless computation model of Blass, Gurevich and Shelah (1999, 2002) is an algorithmic framework for computing isomorphism-invariant properties of unordered structures. Machines in this model have the power of parallel execution, but lack...

An improved sunflower bound.

Jiapeng Zhang

A sunflower with $r$ petals is a collection of $r$ sets so that the intersection of each pair is equal to the intersection of all. Erdos and Rado in 1960 proved the sunflower lemma: for any fixed $r$, any family of sets of size $w$, with at least...

Fooling polytopes

Li-Yang Tan

We give a pseudorandom generator that fools $m$-facet polytopes over $\{0,1\}^n$ with seed length $\mathrm{polylog}(m) \cdot \mathrm{log}(n)$. The previous best seed length had superlinear dependence on $m$. An immediate consequence is a...