# News for November 2013

The action in November is mainly in algebraic property testing.

On Testing Affine-Invariant Properties by Arnab Bhattacharyya (ECCC). As mentioned here, Arnab put together an excellent survey on testing, ahem, affine-invariant properties. It gives a great overview of this area for a non-expert, and is highly recommended for anyone wanting to get a sense of the existing results and open problems.

Algorithmic Regularity for Polynomials and Applications by Arnab Bhattacharyya, Pooya Hatami, and Madhur Tulsiani (Arxiv). Not a pure property testing paper per se. But you can’t complain about papers related to regularity lemmas in a property testing blog. Think of the Szemerédi regularity lemma as the following: given any partition of a graph, one can “refine” it, so that the resulting partition has “few” pieces and is “regular”. Analogously, the regularity lemma for polynomials says that given any set of polynomials, one can “refine” it to get a “small regular” set of polynomials. This has direct applications in Reed-Muller testing (there’s your property testing connection!). This paper is on giving an algorithm that actually constructs this regular set of polynomials. Among other things, this algorithm can be used in decoding of Reed-Muller codes beyond the list-decoding radius.

# Survey on Testing Affine-Invariant Properties

Arnab has put together a wonderful survey on testing affine-invariant properties (ECCC). Consider functions $$f:\mathbb{F}^n_p \to R$$ (where $$R$$ is usually a finite range). A property is called affine-invariant if it closed under affine transformations of the domain. The classic example of such a property is that of being a low-degree polynomial. This is a very rich and beautiful area of research, with the initial inspiration being work in trying to understand what makes a property testable. I will also add that this is a deep (somewhat inaccessible to the non-expert?) area of research, so thanks Arnab for this excellent survey!