A Multidimensional Szemerédi Theorem in the primes (1306.3025v4)
Abstract: Let $A$ be a subset of positive relative upper density of $\PPd$, the $d$-tuples of primes. We prove that $A$ contains an affine copy of any finite set $F\subs\Zd$, which provides a natural multi-dimensional extension of the theorem of Green and Tao on the existence of long arithmetic progressions in the primes. The proof uses the hypergraph approach by assigning a pseudo-random weight system to the pattern $F$ on a $d+1$-partite hypergraph; a novel feature being that the hypergraph is no longer uniform with weights attached to lower dimensional edges. Then, instead of using a transference principle, we proceed by extending the proof of the so-called hypergraph removal lemma to our settings, relying only on the linear forms condition of Green and Tao.