The Theory of Doubly Periodic Pseudo Tangles

Abstract: Doubly periodic tangles (DP tangles) are configurations of curves embedded in the thickened plane, invariant under translations in two transversal directions. In this paper we extend the classical theory of DP tangles by introducing the theory of {\it doubly periodic pseudo tangles} (pseudo DP tangles), which incorporate undetermined crossings called {\it precrossings}, inspired by the theory of pseudo knots. Pseudo DP tangles are defined as liftings of spatial pseudo links in the thickened torus, called {\it pseudo motifs}, and are analyzed through diagrammatic methods that account for both local and global isotopies. We emphasize on {\it pseudo scale equivalence}, a concept defining equivalence between finite covers of pseudo motif diagrams. We investigate the notion of equivalence for these structures, leading to an analogue of the Reidemeister theorem for pseudo DP tangles. Furthermore, we address the complexities introduced by pseudo scale equivalence in defining minimal pseudo motif diagrams. This work contributes to the broader understanding of periodic entangled structures and can find applications in diverse fields such as textiles, materials science and crystallography due to their periodic nature.