Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-26T07:25:48.288Z Has data issue: false hasContentIssue false

Reduced Wu and generalized Simon invariants for spatial graphs

Published online by Cambridge University Press:  20 February 2014

ERICA FLAPAN
Affiliation:
Department of Mathematics, Pomona College, Claremont, CA 91711, U.S.A. e-mail: [email protected]
WILL FLETCHER
Affiliation:
Biophysics Program, Stanford University, Stanford, CA 94305, U.S.A. e-mail: [email protected]
RYO NIKKUNI
Affiliation:
Department of Mathematics, Tokyo Woman's Christian University, 2-6-1 Zempukuji, Suginami-ku, Tokyo 167-8585, Japan. e-mail: [email protected]

Abstract

We introduce invariants of graphs embedded in S3 which are related to the Wu invariant and the Simon invariant. Then we use our invariants to prove that certain graphs are intrinsically chiral, and to obtain lower bounds for the minimal crossing number of particular embeddings of graphs in S3.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Conway, J. and Gordon, C.Knots and links in spatial graphs. J. Graph Theory 7 (1983), 445453.Google Scholar
[2]Flapan, E.Symmetries of Möbius ladders. Math. Ann. 283 (1989), 271283.CrossRefGoogle Scholar
[3]Flapan, E. and Weaver, N.Intrinsic chirality of complete graphs. Proc. Amer. Math. Soc. 1 (1992), 233236.CrossRefGoogle Scholar
[4]Kauffman, L.Formal Knot Theory. Mathematical Notes 30. (Princeton University Press, Princeton, NJ, 1983).Google Scholar
[5]Huh, Y. and Taniyama, K.Identifiable projections of spatial graphs. J. Knot Theory Ramifications 13 (2004), 991998.CrossRefGoogle Scholar
[6]Kauffman, L.Invariants of graphs in three-space. Trans. Amer. Math. Soc. 311 (1989), 697710.Google Scholar
[7]Nikkuni, R.The second skew-symmetric cohomology group and spatial embeddings of graphs. J. Knot Theory Ramifications 9 (2000), 387411.CrossRefGoogle Scholar
[8]Nikkuni, R.Completely distinguishable projections of spatial graphs. J. Knot Theory and its Ramifications 15 (2006), 1119.CrossRefGoogle Scholar
[9]Nikkuni, R.Achirality of spatial graphs and the Simon invariant. Intelligence of Low Dimensional Topology 2006, 239–243. Ser. Knots Everything 40 (World Scientific Publishing, Hackensack, NJ, 2007).Google Scholar
[10]Nikkuni, R.A refinement of the Conway–Gordon theorems. Topology Appl. 156 (2009), 27822794.CrossRefGoogle Scholar
[11]Nikkuni, R.ΔY exchanges and Conway–Gordon type theorems. Intelligence of Low Dimensional Topology, RIMS Kokyuroku 1812 (2012), 114.Google Scholar
[12]Nikkuni, R. and Taniyama, KSymmetries of spatial graphs and Simon invariants. Fund. Math. 205 (2009), 219236.CrossRefGoogle Scholar
[13]Ohyama, Y. Local moves on a graph in $\mathbb{R}^3$. J. Knot Theory Ramifications 5 (1996), 265277.Google Scholar
[14]Shinjo, R. and Taniyama, K.Homology classification of spatial graphs by linking numbers and Simon invariants. Topology Appl. 134 (2003), 5367.CrossRefGoogle Scholar
[15]Simon, J.Topological chirality of certain molecules. Topology 25 (1986), 229235.CrossRefGoogle Scholar
[16]Taniyama, K.Cobordism, homotopy and homology of graphs in R 3. Topology 33 (1994), 509523.CrossRefGoogle Scholar
[17]Taniyama, K.Homology classification of spatial embeddings of a graph. Topology Appl. 65 (1995), 205228.CrossRefGoogle Scholar
[18]Thompson, A.A polynomial invariant of graphs in 3-manifolds. Topology 31 (1992), 657665.Google Scholar
[19]Wu, W. T.On the isotopy of a complex in a Euclidean space I. Scientia Sinica 9 (1960), 2146.Google Scholar
[20]Wu, W. T.A Theory of Imbedding, Immersion and Isotopy of Polytopes in a Euclidean Space, (Science Press, Peking, 1965).Google Scholar
[21]Yamada, S.An invariant of spatial graphs. J. Graph Theory 13 (1989), 537551.Google Scholar
[22]Yokota, Y.Topological invariants of graphs in 3-space, Topology 35 (1996), 7787.CrossRefGoogle Scholar