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only amphicheirals in. Reidemeister's table are the seven identified by Tait in 1884. Diagrams of the 165 prime. 10-crossing knot types are appended. (Murasugi.
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY Volume 45, Number 2, August

1974

ON THE CLASSIFICATION OF KNOTS KENNETH A. PERKO, JR. ABSTRACT. Linking numbers between branch curves of irregular covering spaces of knots are used to extend the classification of knots through ten crossings and to show that the only amphicheirals in Reidemeister's table are the seven identified by Tait in 1884. Diagrams of the 165 prime 10-crossing knot types are appended. (Murasugi and the author have proven them prime; Conway claims proof that the tables are complete.) Including the trivial type, there are precisely 250 prime knots with ten or fewer crossings.

This

knots

paper

tabled

completes

by Tait

the classification

[9] and Little

for the six remaining

knots

(by knot type)

[4] and solves

in Reidemeister's

of the

10-crossing

the amphicheirality

table

problem

[6, pp. 70—72].

The method of proof is that set forth in [6, Chapter III, §15]-Iinking numbers

between

branch

[3, §5 and Reference The coverings

curves

considered

regular

p-gon)

stricted

to representations

sheeted

covering

the curve

dihedral

between

x with the curve linking

number

Received

group

sending

between

sum of those

ber between

are those

spaces.

1 See also

of index and

on four letters.

curve

1. Similarly,

by the editors

of branching v

1 and the sum of those

of index

of index

of a

and

v.

of index number

of index

is

2 and the

is the linking

num-

2 in a p-

in such

a

2 which have linking 2 which

number have

1.

July 3, 1973 and, in revised

AMS(MOS)subject classifications

of a

are re-

index

(p odd)

1 and the sum of all curves

y with the curve

The latter

into transpositions

v Ax, y) is the linking

the sum of all curves of index

out of representations

2p (the group of symmetries

meridians

the branch

of index

covering

arising

group of order

or the symmetric

number

algebraic

covering

13].

knot group onto the dihedral

the linking

of irregular

form, September

12, 1973.

(1970). Primary 55A25, 55A10.

Key words and phrases. Knots with ten crossings, amphicheirality, linking numbers between branch curves of irregular covering spaces of knots. 1 These linking numbers may be computed geometrically as discussed in the author's paper On covering spaces of knots, to appear in Glasnik Matematicki 9 (29) (1974). Calculations with respect to particular examples are available on request. Copyright © 1974, American Mathematical Society

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262

263

ON THE CLASSIFICATION OF KNOTS Since

the index

a branched numbers

(taken

topological

induced

invariants

there

the set of such

to a simultaneous

are known

viously

onto a given reversal

units

nonamphicheiral

numbers

and a representational

table

of 2-bridged

include

knots

group)

table,

63, 8,,

means,

theorems

prove

non-

orientation with

8g, 812, 817 and

[l,

The linking

six have

including

pre-

the

[7, p. 170], signatures

dihedral

of Bürde

has been extended

919, 923 and 9,,.)

also

of

linking are

is nonsymmetric

4.,

by various

in 3-sheeted

invariant

which

(for a particular

[8] and all but the following

[6, p. 31], Schubert's

[5, p. 400], linking

of Si D k, such

of sign.

to be amphicheiral

been proven

Minkowski

autohomeomorphisms

of k in S numbers

Of the 84 knots in Reidemeister's 8,„

under

is more than one representation)

of the complement

where

and all representations

respect

is preserved

by autohomeomorphisms

as a set where

amphicheirality of S

of branching

covering

covering

p. 120].

(Note

by Murasugi

numbers tabled

spaces that

[3, p. 200] Schubert's

[unpublished]

to

below prove that

all six are nonamphicheiral.

820

v9=±2,

930

iy3 =±8,

924

v9=±2,

933

v6l(6,-6)=

Of the 166 10-crossing been previously

table)

by the rational

fractions

told, to the parameters coverings)

type,

[2].

together

Table

(both

either

associated

1 sets

shown

in Figure

1, the pair

tected

duplication

in Little's

(8 times),

949

f, = ±16/5

(6 times).

from each

by their

with 2-bridged

10

knots

examples,

which

10

newly

turns

all but 31 have

and from the knots

their grouped

2-sheeted

1

we are cyclic

by polynomial

30 of them.

out to be a previously

License or copyright restrictions may apply to redistribution; see http://www.ams.org/journal-terms-of-use

in

or, in 3 cases,

(and corresponding,

distinguish

table.

Figure

tables,

polynomials

which constitute

forth these

numbers

other

Alexander

of the lens spaces

with linking

iy = ±6/7

knots in the Tait-Little

distinguished

Reidemeister's

±4,

941

unde-

As

264

K. A. PERKO, JR.

Table 1

10,

±4

10,

+4

10an

5,

±4

7s

±4

10,

±8

10,

±8

±22/3 ±22/3

±4

±22/3 10, 10,

±6

10,

±2

10,

±4

102

±6

10,

±6/5

±4

I0„,

±6

±4/5 ±4/5 ±4/5 ±4/5 ±4/5 +4/5 104

1046

±10

±2 10,

±4

±6/5

820

0

±■1

±4 ±4

±4 ±4

8,6

±12

±4

±6

10, 10,

10.,v

±6

±4

10«

U4/5

10, 928

±4

929

±10

103VJ

10,

±12

10,

±24/5 ±24/5 ±24/5 ±24/5 ±24/5 +56/5

±10/3 114/3 ±14/3

±2

10,

ho

+4

'O4V,,,

+12

±2

10, 93a

±14

10.„ u69

±4

»o« 0

10,

102

10, 1077 940

«

1042

±2

10,

±4

±52/11

"29(2.-2)

10,

0 su

«2/11

6VI

«2/11

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10,

±10

265

ON THE CLASSIFICATION OF KNOTS

PRIME KNOTS WITH TEN CROSSINGS Taken from the tables

of P. G. Tait

and C. N. Little

[Trans. Roy. Soc. Edinburgh 32 (1885) and 39 (1900)] (The knots

duplication

in Little's

with two bridges

table

has been omitted and

are grouped

at the beginning.)

1

3

11

14

15

16

20

21

22

24

37

41

43

48

49

51

52

58

60

61

62

65

66

67

68

71

74

76

77

78

79

80

81

101

102

104

105

106

107

108

117

119

120

121

122

2

4

5

6

7

8

9

10

12

13

17

18

19

23

25

26

27

28

29

30

31

32

33

34

35

36

38

39

40

42

44

45

46

47

50

53

54

55

56

57

59

63

64

69

70

72

73

75

82

83

64

85

66

87

88

89

90

91

92

93

94

95

96

97

98

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266

K. A. PERKO, JR.

99

100

103

109

110

111

112

113

114

115

116

144 3VI

145 3VII

146 3VIII

147 3IX

148 3X

149 41

150 411

151 4III

152 4IV

153 4V

154 4VI

155

156

157

158

159

160

161

162

163

164

165

4VII

4VIII

51

511

6l

611

6111

6IV

6V

6VII

6VIII

REFERENCES 1.

G. Bürde,

Darstellungen

von Knotengruppen

und eine

Abh. Math. Sem. Univ. Hamburg 35 (1970), 107-120. 2. braic

J.H.

Conway,

properties,

An enumeration

Computational

of knots

Problems

and links,

in Abstract

R. H. Fox,

(1970), 193-201.

Metacyclic

invariants

of knots

and some

/\lgebra

1967), Pergamon Press, Oxford, 1970, pp. 329-358. 3-

Knoteninvariante,

MR 43 #2695of their

(Proc.

Conf.,

algeOxford,

MR 41 #2661. and links,

Canad.

J. Math.

22

MR41#6197.

4. C. N. Little,

Non-alternate

± knots,

Trans.

Roy. Soc. Edinburgh

39 (1900),

771-778, plates I, II, III. 5-

K. Murasugi,

Oti a certain

Math. Soc. 117 (1965), 387-422. 6.

biete,

K. Reidemeister,

numerical

Knotentheorie,

Band 1, Springer-Verlag,

invariant

of link

types,

Trans.

Amer.

MR 30 #1506. Berlin,

Ergebnisse

der Math,

und ihrer

Grenzge-

1932.

7. H. Schubert, Knoten mit zwei Brücken, Math. Z. 65 (1956), 133—170. MR 18, 498. 8.

P. G. Tait,

The first

seven

orders

of knottiness,

Trans.

Roy.

Soc.

Edinburgh

32(1884), plate 44. 9. -,

Tenfold knottiness,

Trans.

Roy. Soc. Edinburgh

32 ( 1885), plates

80, 81. 400 Central Park West Apt. 16-P, New York, New York 10025 License or copyright restrictions may apply to redistribution; see http://www.ams.org/journal-terms-of-use