Entwining tetrahedron maps

Abstract

We present three non-equivalent procedures to obtain entwining (non-constant) tetrahedron maps. Given a tetrahedron map, the first procedure incorporates its underlying symmetry group. With the second procedure we obtain several classes of entwining tetrahedron maps by considering certain compositions of pentagon with reverse-pentagon maps which satisfy certain compatibility relations the so-called ten-term relations. Using the third procedure, provided that a given tetrahedron map admits at least one companion map (partial inverse), we obtain entwining set theoretical solutions of the tetrahedron equation.