Fox n-coloring of knots
E941102
Fox n-coloring of knots is a classical algebraic technique in knot theory that assigns colors (integers modulo n) to arcs of a knot diagram according to specific rules, producing an invariant useful for distinguishing non-equivalent knots.
Statements (39)
| Predicate | Object |
|---|---|
| instanceOf |
algebraic technique in knot theory
ⓘ
coloring invariant ⓘ knot invariant ⓘ |
| appliesTo |
knot diagrams
ⓘ
link diagrams ⓘ |
| canBeComputedBy | solving linear equations modulo n ⓘ |
| canBeComputedFrom | Wirtinger presentation of the knot group ⓘ |
| canBeFormulatedAs | system of linear equations over Z_n ⓘ |
| canDistinguish | non-equivalent knots ⓘ |
| dependsOn | choice of modulus n but not on particular diagram of the knot ⓘ |
| domain | oriented knots in S^3 ⓘ |
| field |
knot theory
ⓘ
low-dimensional topology ⓘ |
| generalizationOf | simple 3-coloring invariants of knots ⓘ |
| hasAlgebraicInterpretation | module over Z_n associated to the knot ⓘ |
| hasRule |
a coloring is nontrivial if not all arcs receive the same color
ⓘ
at each crossing, twice the color of the over-arc equals the sum of the colors of the under-arcs modulo n ⓘ each arc of the knot diagram is assigned a color in Z_n ⓘ |
| historicalContext | introduced in the mid-20th century ⓘ |
| invariantUnder | Reidemeister moves NERFINISHED ⓘ |
| isStableUnder | ambient isotopy of knots ⓘ |
| isTrivialIf | only monochromatic colorings exist ⓘ |
| namedAfter | Ralph H. Fox NERFINISHED ⓘ |
| nontrivialColoringImplies | knot determinant is divisible by n ⓘ |
| output |
cardinality of the set of valid colorings modulo n
ⓘ
set of all valid colorings modulo n ⓘ |
| relatedTo |
determinant of a knot
ⓘ
dihedral group representations of knot groups ⓘ first homology of the 2-fold branched cover of S^3 over the knot ⓘ homomorphisms from the knot group to the dihedral group D_{2n} ⓘ |
| requires | integer n ≥ 2 ⓘ |
| specialCase | 3-coloring of knots ⓘ |
| usedFor |
constructing simple examples in introductory knot theory
ⓘ
distinguishing the trefoil knot from the unknot ⓘ |
| uses |
arcs of a knot diagram
ⓘ
integers modulo n ⓘ knot diagrams ⓘ |
| yields |
knot invariant
ⓘ
number of distinct n-colorings of a knot diagram ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.