DOI QR코드

DOI QR Code

2n-Moves and the Γ-Polynomial for Knots

  • Hideo Takioka (School of Mechanical Engineering, College of Science and Engineering, Kanazawa University)
  • 투고 : 2020.08.22
  • 심사 : 2021.07.12
  • 발행 : 2024.09.30

초록

A 2n-move is a local change for knots and links which changes 2n-half twists to 0-half twists or vice versa for a natural number n. In 1979, Yasutaka Nakanishi conjectured that the 4-move is an unknotting operation. This is still an open problem. It is known that the Γ-polynomial is an invariant for oriented links which is the common zeroth coefficient polynomial of the HOMFLYPT and Kauffman polynomials. In this paper, we show that the 4k-move is not an unknotting operation for any integer k(≥ 2) by using the Γ-polynomial, and if Γ(K; -1) ≡ 9 (mod 16) then the knot K cannot be deformed into the unknot by a single 4-move. Moreover, we give a one-to-one correspondence between the value Γ(K; -1) (mod 16) and the pair (a2(K), a4(K)) (mod 2) of the second and fourth coefficients of the Alexander-Conway polynomial for a knot K.

키워드

과제정보

This work was supported by JSPS KAKENHI Grant Number JP22K13911.

참고문헌

  1. R. H. Fox, Congruence classes of knots, Osaka Math. J., 10(1958), 37-41.
  2. P. Freyd, D. Yetter, J. Hoste, W. B. R. Lickorish, K. Millett and A. Ocneanu, A new polynomial invariant of knots and links, Bull. Amer. Math. Soc., 12(1985), 239-246.
  3. H. Fujii, First common terms of the HOMFLY and Kauffman polynomials, and the Conway polynomial of a knot, J. Knot Theory Ramifications, 8(4)(1999), 447-462.
  4. L. H. Kauffman, An invariant of regular isotopy, Trans. Amer. Math. Soc., 318(1990), 417-471.
  5. A. Kawauchi, On coefficient polynomials of the skein polynomial of an oriented link, Kobe J. Math., 11(1994), 49-68.
  6. A. Kawauchi, A Survey of Knot Theory, Birkhauser, Basel, (1996).
  7. A. Kawauchi, Lectures on knot theory (in Japanese), Kyoritsu Shuppan, (2007).
  8. S. Kinoshita, On Wendt's theorem of knots, Osaka Math. J., 9(1957), 61-66.
  9. W. B. R. Lickorish and K. C. Millett, A polynomial invariant of oriented links, Topology, 26(1987), 107-141.
  10. W. B. R. Lickorish, Polynomials for links, Bull. London Math. Soc., 20(1988), 558-588.
  11. H. Murakami, A recursive calculation of the Arf invariant of a link, J. Math. Soc. Japan, 38(2)(1986), 335-338.
  12. Y. Nakanishi, Fox's congruence modulo (2, 1), Surikaisekikenkyusho Kokyuroku 518(1984), 96-101.
  13. Y. Nakanishi and S. Suzuki, On Fox's congruence classes of knots, Osaka J. Math., 24(1987), 217-225.
  14. J. H. Przytycki and P. Traczyk, Invariants of links of Conway type, Kobe J. Math., 4(1987), 115-139.
  15. J. H. Przytycki, tk moves on links, Braids (Santa Cruz, CA, 1986), 615-656, Contemp. Math., 78, Amer. Math. Soc., Providence, RI, 1988.
  16. H. Takioka, A characterization of the Γ-polynomials of knots with clasp number at most two, J. Knot Theory Ramifications, 26(4)(2017), 1750013.