Existential 0-definability of henselian valuation rings
arXiv:1307.1956
Abstract
Recently, Anscombe and Koenigsmann gave an existential 0-definition of the ring of formal power series F[[t]] in its quotient field in the case where F is finite. We extend their method in several directions to give general definability results for henselian valued fields with finite or pseudo-algebraically closed residue fields.
minor corrections, Theorem 4.1 strengthened, Remark 4.2 added