We present a new method to produce simple formulas for 1-cocycles of knots over the integers, inspired by Polyak-Viro's formulas for finite-type knot invariants. We conjecture that these 1-cocycles represent finite-type cohomology classes in the sense of Vassiliev. An example of degree 3 is studied, and shown to coincide over Z 2 with the Teiblum-Turchin cocycle v 1 3 .The study of the topology of the space of knots was initiated in 1990 by Vassiliev [23], who defined finite-type cohomology classes by applying ideas from the finitedimensional affine theory of plane arrangements to the infinite-dimensional theory of long knots in 3-space. Here, of finite type means of finite complexity, in some sense, hence hopefully computable. Independently, outstanding general results on the topology of knot spaces have been obtained by Hatcher [11], leading to the idea that higher dimensional invariants of knots -in particular, 1-cocycles -should capture information about the geometry of a knot (see [7]). The zeroth level of Vassiliev's theory, known as finite-type knot invariants, has been extensively studied in the subsequent years [1,2,9,13]. However at the first level -that of 1-cocycles -only one example, in degree 3, has been proved to exist by Teiblum and Turchin, and then actually described by Vassiliev with a formula over Z 2 [22,25]. Since then, no progress has been made, probably because of the technicity of Vassiliev's construction and the apparent difficulty of turning it into a systematic method: indeed, it involves singularity theory with differential geometric 1540004-1 J. Knot Theory Ramifications 2015.24. Downloaded from www.worldscientific.com by CALIFORNIA INSTITUTE OF TECHNOLOGY on 06/27/16. For personal use only.