English

Arrow diagrams on spherical curves and computations

Geometric Topology 2019-08-20 v1

Abstract

We give a definition of an integer-valued function iαixi\sum_i \alpha_i x ^*_i derived from arrow diagrams for the ambient isotopy classes of oriented spherical curves. Then, we introduce certain elements of the free Z\mathbb{Z}-module generated by the arrow diagrams with at most ll arrows, called relators of Type~(Iˇ\check{\rm{I}}) ((SI ⁣Iˇ\check{\rm{SI\!I} }), (WI ⁣Iˇ\check{\rm{WI\!I}}), (SI ⁣I ⁣Iˇ\check{\rm{SI\!I\!I}}), or (WI ⁣I ⁣Iˇ\check{\rm{ WI\!I\!I}}), resp.), and introduce another function iαix~i\sum_i \alpha_i \tilde{x}^*_i to obtain iαixi\sum_i \alpha_i x^*_i. One of the main results shows that if iαix~i\sum_i \alpha_i \tilde{x}^*_i vanishes on finitely many relators of Type~(Iˇ\check{\rm{I}}) ((SI ⁣Iˇ\check{\rm{SI\!I}}) , (WI ⁣Iˇ\check{\rm{WI\!I}}), (SI ⁣I ⁣Iˇ\check{\rm{SI\!I\!I}}), or (WI ⁣I ⁣Iˇ\check{\rm{WI\! I\!I}}), resp.), then iαix~\sum_i \alpha_i \tilde{x} is invariant under the deformation of type RI\rm{RI} (strongRI ⁣I\rm{RI\!I}, weakRI ⁣I\rm{RI\!I}, strongRI ⁣I ⁣I\rm{RI\!I\!I}, or weakRI ⁣I ⁣I\rm{RI\!I\!I}, resp.). The other main result is that we obtain functions of arrow diagrams with up to six arrows. This computation is done with the aid of computers.

Keywords

Cite

@article{arxiv.1908.06085,
  title  = {Arrow diagrams on spherical curves and computations},
  author = {Noboru Ito and Masashi Takamura},
  journal= {arXiv preprint arXiv:1908.06085},
  year   = {2019}
}

Comments

44 pages, 16 figures, 19 tables. arXiv admin note: text overlap with arXiv:1905.01418

R2 v1 2026-06-23T10:49:22.134Z