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Title: Groups of Order p^m Which Contain Cyclic Subgroups of Order p^(m-3)Author: Lewis Irving Neikirk
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*** START OF THE PROJECT GUTENBERG EBOOK GROUPS OF ORDER P^M ***
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Trang 2GROUPS OF ORDER pm WHICH CONTAIN
byLEWIS IRVING NEIKIRK
sometime harrison research fellow in mathematics
1905
Trang 3INTRODUCTORY NOTE.
This monograph was begun in 1902-3 Class I, Class II, Part I, and the conjugate groups of Class III, which contain all the groups with independentgenerators, formed the thesis which I presented to the Faculty of Philosophy
self-of the University self-of Pennsylvania in June, 1903, in partial fulfillment self-of therequirements for the degree of Doctor of Philosophy
The entire paper was rewritten and the other groups added while the authorwas Research Fellow in Mathematics at the University
I wish to express here my appreciation of the opportunity for scientific search afforded by the Fellowships on the George Leib Harrison Foundation atthe University of Pennsylvania
re-I also wish to express my gratitude to Professor George H Hallett for hiskind assistance and advice in the preparation of this paper, and especially toexpress my indebtedness to Professor Edwin S Crawley for his support andencouragement, without which this paper would have been impossible
Lewis I Neikirk
University Of Pennsylvania, May, 1905.
Trang 4GROUPS OF ORDER pm, WHICH CONTAIN CYCLIC
bylewis irving neikirkIntroduction
The groups of order pm, which contain self-conjugate cyclic subgroups oforders pm−1, and pm−2
respectively, have been determined by Burnside,2andthe number of groups of order pm, which contain cyclic non-self-conjugate sub-groups of order pm−2
has been given by Miller.3Although in the present state of the theory, the actual tabulation of allgroups of order pm is impracticable, it is of importance to carry the tabulation
as far as may be possible In this paper all groups of order pm(p being an oddprime) which contain cyclic subgroups of order pm−3 and none of higher orderare determined The method of treatment used is entirely abstract in characterand, in virtue of its nature, it is possible in each case to give explicitly thegenerational equations of these groups They are divided into three classes, and
it will be shown that these classes correspond to the three partitions: (m − 3, 3),(m − 3, 2, 1) and (m − 3, 1, 1, 1), of m
We denote by G an abstract group G of order pm containing operators oforder pm−3 and no operator of order greater than pm−3 Let P denote one
of these operators of G of order pm−3 The p3 power of every operator in G iscontained in the cyclic subgroup {P }, otherwise G would be of order greater than
pm The complete division into classes is effected by the following assumptions:
I There is in G at least one operator Q1, such that Qp12 is not contained in{P }
II The p2 power of every operator in G is contained in {P }, and there is atleast one operator Q1, such that Qp1 is not contained in {P }
III The pth power of every operator in G is contained in {P }
1 Presented to the American Mathematical Society April 25, 1903.
2 Theory of Groups of a Finite Order, pp 75-81.
3 Transactions, vol 2 (1901), p 259, and vol 3 (1902), p 383.
Trang 5The number of groups for Class I, Class II, and Class III, together with thetotal number, are given in the table below:
We have the relation
There is in G, a subgroup H1of order pm−2, which contains {P }
self-conjugate-ly.5 The subgroup H1is generated by P and some operator Qy1Pxof G; it thencontains Qy1 and is therefore generated by P and Qp12; it is also self-conjugate
in H2= {Qp1, P } of order pm−1, and H2 is self-conjugate in G
From these considerations we have the equations6
Q−p1 2P Qp12= P1+kpm−4,(2)
Q−p1 P Qp1= Qβp1 2Pα1,(3)
Q−11 P Q1= Qbp1 Pa1.(4)
4 With J W Young, On a certain group of isomorphisms, American Journal of matics, vol 25 (1903), p 206.
Mathe-5
Burnside: Theory of Groups, Art 54, p 64.
6 Ibid., Art 56, p 66.
Trang 62 Determination of H1 Derivation of a formula for [yp , x] —From (2),
by repeated multiplication we obtain
[−p2, x, p2] = [0, x(1 + kpm−4)];
and by a continued use of this equation we have
[−yp2, x, yp2] = [0, x(1 + kpm−4)y] = [0, x(1 + kypm−4)] (m > 4)and from this last equation,
(5) [yp2, x]s=syp2, x{s + k s2ypm−4}
3 Determination of H2 Derivation of a formula for [yp, x]s.—It followsfrom (3) and (5) that
α1= 1 + α2p2,the congruence
(1 + α2p2)p− 1
α2p3 (α2+ hβ)p3≡ kpm−4 (mod pm−3);
and so
(α2+ hβ)p3≡ 0 (mod pm−4),since
(1 + α2p2)p− 1
α2p3 ≡ 1 (mod p2)
Trang 7From the last congruences
(α2+ hβ)p3≡ kpm−4 (mod pm−3)
(6)
Equation (3) is now replaced by
Q−p1 P Q−p1 = Qβp1 2P1+α2 p2.(7)
From (7), (5), and (6)
[−yp, x, yp] =βxyp2, x{1 + α2yp2} + βk x
2ypm−4
A continued use of this equation gives
(8) [yp, x]s= [syp + β s2xyp2,
and from (1) and (2)
Trang 8These defining relations may be presented in simpler form by a suitablechoice of the second generator Q1 From (9), (6), (8) and (10)
[1, x]p3 = [p3, xp3] = [0, (x + h)p3] (m > 6),and, if x be so chosen that
x + h ≡ 0 (mod pm−6),
Q1Px is an operator of order p3 whose p2 power is not contained in {P } Let
Q1Px= Q The group G is generated by Q and P , where
corre-[−y, 1, y] = [byp, 1 + aypm−6] (m > 8)
It is important to notice that by placing y = p and p2 in the precedingequation we find that8
b ≡ β (mod p), a ≡ α ≡ k (mod p3) (m > 7)
A combination of the last equation with (8) yields9
(12) [−y, x, y] = [bxyp + b2 x2yp2,
x(1 + aypm−6) + ab x2ypm−5+ ab2 x3ypm−4] (m > 8)
7 For m = 8 it is necessary to add a 2 y
2 p 4 to the exponent of P and for m = 7 the terms a(a +abp2 ) y2p 2 + a 3 y
3 p 3 to the exponent of P , and the term ab y2p 2 to the exponent of Q The extra term 27ab 2 k y3 is to be added to the exponent of P for m = 7 and p = 3.
Trang 9(m > 8)
5 Transformation of the Groups.—The general group G of Class I is ified, in accordance with the relations (2) (11) by two integers a, b which (see(11)) are to be taken mod p3, mod p2, respectively Accordingly setting
spec-a = spec-a1pλ, b = b1pµ,where
where
Q01= Q0y0P0x0pm−6, and P10 = Q0yP0x,
10 For m = 8 it is necessary to add the term 1axy s2[ 1 y(2s − 1) − 1]p 4 to the exponent of
P , and for m = 7 the terms
3s − 1
3 +a
2 b 2
s(s − 1) 2 (s − 4)
s
3 yp 3 o with the extra terms
27abxy
n bk 3!
s
2 y 2 − (2s − 1)y + 2 s
3 + x(b 2 k + a2)(2y2+ 1) s3o
, for p = 3, to the exponent of P , and the termsab2s − 1 y − 1 s xyp 2 to the exponent of Q.
Trang 10with y and x prime to p.
Since
Q−1P Q = QbpP1+apm−6,then
Q0−11 P10Q01= Q0bp1 P01+ap1 m−6,
or in terms of Q0, and P0
y + b0xy0p + b02 x2y0p2, x(1 + a0y0pm−6) + a0b0 x2y0pm−5
+ a0b02 x3y0pm−4 = [y + by0p, x + (ax + bx0p)pm−6] (m > 8)and
by0 ≡ b0xy0+ b02 x2y0p (mod p2),(14)
ax + bx0p ≡ a0y0x + a0b0 x2y0p + a0b02 x3y0p2 (mod p3)
(15)
The necessary and sufficient condition for the simple isomorphism of these twogroups G(a, b) and G(a0, b0) is, that the above congruences shall be consistentand admit of solution for x, y, x0 and y0 The congruences may be written
b1pµ≡ b01xpµ0+ b021 x2p2µ0+1 (mod p2),
a1xpλ+ b1x0pµ+1≡
y0{a01xpλ0+ a01b01 x2pλ0+µ0+1+ a01b021 x3pλ0+2µ0+2} (mod p3).Since dv[x, p] = 1 the first congruence gives µ = µ0 and x may always be sochosen that b1= 1
We may choose y0 in the second congruence so that λ = λ0and a1= 1 exceptfor the cases λ0≥ µ + 1 = µ0+ 1 when we will so choose x0 that λ = 3
The type groups of Class I for m > 811are then given by
(I) G(pλ, pµ) : Q−1P Q = Qp1+µP1+pm−6+λ, Qp3 = 1, Ppm−3 = 1
µ = 0, 1, 2; λ = 0, 1, 2; λ ≥ µ;
µ = 0, 1, 2; λ = 3
!
Of the above groups G(pλ, pµ) the groups for µ = 2 have the cyclic group {P } self-conjugate, while the group G(p3, p2) is the abelian group oftype (m − 3, 3)
sub-11 For m = 8 the additional term ayp appears on the left side of the congruence (14) and G(1, p 2 ) and G(1, p) become simply isomorphic The extra terms appearing in congruence (15) do not effect the result For m = 7 the additional term ay appears on the left side of (14) and G(1, 1), G(1, p), and G(l, p 2 ) become simply isomorphic, also G(p, p) and G(p, p 2 ).
Trang 112 Groups with independent generators.
Consider the first possibility in the above paragraph There is in H2, a group H1of order pm−2, which contains {P } self-conjugately.12 H1is generated
sub-by Qp1 and P H2contains H1 self-conjugately and is itself self-conjugate in G.From these considerations13
Q−p1 P Qp1 = P1+kpm−4,(2)
Q−11 P Q = Qβp1 Pα1.(3)
[−p, 1, p] = αp1− 1
α1− 1βp, α
p 1
1 + βk2
Trang 12Equation (3) now becomes
2αk
13!s(s − 1)(2s − 1)y
Q1Pxwill be the required Q of order p2
Placing h = 0 in congruence (5) we find
α2p2≡ kpm−4 (mod pm−3)
Let α2= αpm−6 H2 is then generated by
Qp2 = 1, Ppm−3 = 1
Two of the preceding formulæ now become
[−y, x, y] =βxyp, x(1 + αypm−5) + βk x2ypm−4,
(8)
[y, x]s= [sy + Usp, xs + Wspm−5],(9)
where
Us= β s2xyand14
Trang 13R−11 Q R1= Qd1Pc1 p m−5
.(12)
In order to ascertain the forms of the constants in (11) and (12) we obtain from(12), (11), and (9)
[−p, 1, 0, p] = [0, dp1+ M p, N pm−5]
By (10) and (8)
Rp1Q Rp1= P−µpQ Pµp = Q P−aµpm−4.From these equations we obtain
dp1 ≡ 1 (mod p) and d1≡ 1 (mod p)
Let d1= 1 + dp Equation (12) is replaced by
Trang 14and from the last two equations
ap1≡ 1 (mod pm−5)and
a1≡ 1 (mod pm−6) (m > 6); a1≡ 1 (mod p) (m = 6).Placing a1= 1 + a2pm−6 (m > 6); a1= 1 + a2p (m = 6)
K ≡ 0 (mod p),and16
The preceding relations will be simplified by taking for R1an operator of order
p This will be effected by two transformations
and if y be so chosen that
λ + y ≡ 0 (mod p),
R2= R1Qy is an operator such that Rp2 is in {P }
Let
Rp2 = Plp.Using R2 in the place of R1, from (15), (9) and (14)
[1, 0, x]p=hp, 0, xp +ax
2 p
m−4i=h0, 0, (x + l)p +ax
2 pm−4i,
16 K has an extra term for m = 6 and p = 3, which reduces to 3b 1 c 1 This does not affect the reasoning except for c 1 = 2 In this case change P2to P and c 1 becomes 1.
17 The extra terms appearing in the exponent of P for m = 6 do not alter the result.
Trang 15and if x be so chosen that
x + l +ax
2 pm−5≡ 0 (mod pm−4),
then R = R2Pxis the required operator of order p
Rp= 1 is permutable with both Q and P Preceding equations now assumethe final forms
Q−1P Q = QβpP1+apm−5,(15)
R−1P R = QbpP1+apm−4,(16)
R−1Q R = Q1+dpPcpm−4,(17)
with Rp= 1, Qp2= 1, Ppm−3 = 1
The following derived equations are necessary18
[0, −y, x, 0, y] =0, βxyp, x(1 + αypm−5) + αβ x2ypm−4,
5 Transformation of the groups All groups of this section are given byequations (15), (16), and (17) with a, b, β, c, d = 0, 1, 2, · · · , p − 1, and α =
0, 1, 2, · · · , p2− 1, independently Not all these groups, however, are distinct.Suppose that G and G0 of the above set are simply isomorphic and that thecorrespondence is given by
R01, Q01, P10
,
in which
R01= R0z00Q0y00pP0x00pm−4,
Q01= R0z0Q0y0P0x0pm−5,
P10 = R0zQ0yP0x,
18 For m = 6 the term a 2 x
2 xp 2 must be added to the exponent of P in (18).
19 When m = 6 the following terms are to be added to V s : a22x
n
s(s−1)(2s−1) 3! y2− s2yop.
Trang 16where x, y and z are prime to p.
The operators R10, Q01, and P10 must be independent since R, Q, and P are,and that this is true is easily verified The lowest power of Q0
1in {P0
1} is Q0p2
1 = 1and the lowest power of R01 in {Q01, P10} is R0p
1= 1 Let Q0s10 = P0sp1m−5.This in terms of R0, Q0, and P0 is
h
s0z0, y0s0+ d0 s20z0p , s0x0pm−5+ c0 s20y0z0pm−4i= [0, 0, sxpm−5].From this equation s0 is determined by
s0z0 ≡ 0 (mod p)
y0{s0+ d0 s2z0p} ≡ 0 (mod p2),which give
s0y0≡ 0 (mod p2)
Since y0 is prime to p
s0≡ 0 (mod p2)and the lowest power of Q01 contained in {P10} is Q0p2
[z, y + θ1p, x + φ1pm−5] = [z, y + βy0p, x(1 + αpm−5) + βxpm−4],(22)
[z, y + θ2p, x + φ2pm−4] = [z, y + by0p, x(1 + apm−4) + bx0pm−4],(23)
[z0, y0+ θ3p, (x0+ φ3p)pm−5] = [z0, y0(1 + dp), x(1 + dp)pm−5+ cxpm−4],(24)
Trang 17φ1≡ αx + βx0p (mod p2),(II)
θ2≡ by0 (mod p),(III)
φ2≡ ax + bx0 (mod p),(IV)
θ3≡ dy0 (mod p),(V)
G0 is then taken from the simplest of the remaining cases and we proceed asabove until all the cases are exhausted
Let κ = κ1pκ2, and dv1[κ1, p] = 1 (κ = a, b, α, β, c, and d)
The six sets are given in the table below
Trang 18The groups marked (*) divide into two or three parts.
Let ad − bc = θ1pθ2, α1d − βc = φ1pφ2 and α1b − aβ = χ1pχ2 with θ1, φ1,and χ1 prime to p
Trang 196 Types.
The type groups are given by equations (15), (16) and (17) with the values
of the constants given in Table IV
b0xz0 ≡ βy0 (mod p),(I)
α0y0 ≡ α (mod p),(II)
b0xz00≡ by0 (mod p),(III)
α0xy00+ α0b0 x2z00+ c0yz00≡ ax + bx0 (mod p),(IV)
d ≡ 0 (mod p),(V)
c0y0z00≡ cx (mod p)
(VI)
Since z0 is unrestricted (I) gives β ≡ 0 or 6≡ 0 (mod p)
From (II) since y06≡ 0, α 6≡ 0 (mod p)
From (III) since x, y0, z006≡ 0, b 6≡ 0 (mod p)
In (IV) b 6≡ 0 and x0 is contained in this congruence alone, and, therefore, amay be taken ≡ 0 or 6≡ 0 (mod p)
(V) gives d ≡ 0 (mod p) and (VI), c 6≡ 0 (mod p)
Elimination of y0 between (III) and (VI) gives
b0c0z002≡ bc (mod p)
Trang 20so that bc is a quadratic residue or non-residue (mod p) according as bc is aresidue or non-residue.
The types are given by placing a = 0, b = 1, α = 1, β = 0, c = κ, and d = 0where κ has the two values, 1 and a representative non-residue of p
C2.The congruences for this case are
d0(yz0− y0z) ≡ βy0 (mod p),(I)
α01xy0+ a0xz0≡ α1x + βx0 (mod p),(II)
d0yz00≡ by0 (mod p),(III)
a0xz00≡ ax + bx0 (mod p),(IV)
d0z00≡ d (mod p),(V)
cx + dx0≡ 0 (mod p)
(VI)
Since z appears in (I) alone, β can be either ≡ 0 or 6≡ 0 (mod p) (II)
is linear in z0 and, therefore, α ≡ 0 or 6≡ 0 (mod p), (III) is linear in y and,therefore, b ≡ 0 or 6≡ 0
Elimination of x0 and z00 between (IV), (V), and (VI) gives
a0d2≡ d0(ad − bc) (mod p)
Since z00 is prime to p, (V) gives d 6≡ 0 (mod p), so that ad − bc 6≡ 0 (mod p)
We may place b = 0, α = p, β = 0, c = 0, d = 1, then a will take the values
1, 2, 3, · · · , p − 1 giving p − 1 types
D1.The congruences for this case are
d0(yz0− y0z) ≡ βy0 (mod p),(I)
α1x + βx0 ≡ 0 (mod p),(II)
d0yz00≡ by0 (mod p),(III)
ax + bx0 ≡ 0 (mod p),(IV)
d0z00≡ d (mod p),(V)
cx + dx0 ≡ 0 (mod p)
(VI)
z is contained in (I) alone, and therefore β ≡ 0 or 6≡ 0 (mod p)
(III) is linear in y, and b ≡ 0 or 6≡ 0 (mod p)
(V) gives d 6≡ 0 (mod p)
Elimination of x0 between (II) and (VI) gives α1d − βc ≡ 0 (mod p), andbetween (IV) and (VI) gives ad − bc ≡ 0 (mod p) The type group is derived
by placing a = 0, b = 0, α = 0, β = 0, c = 0 and d = 1
Trang 21Section 2.
1 Groups with dependent generators In this section, G is generated by Q1and P where
There is in G, a subgroup H1, of order pm−2, which contains {P }
self-conjugate-ly.20 H1 either contains, or does not contain Qp1 We will consider the secondpossibility in the present section, reserving the first for the next section
2 Determination of H1 H1 is generated by P and some other operator R1
and
[y, x]s=hsy, xs + k s
2ypm−4 i(5)
Placing s = p and y = 1 in (5) we have, from (2)
[R1Px]p= Rp1Pxp= P(l+x)p.Choosing x so that
of order pm−1 which contains H1 self-conjugately H2 is generated by H1 and
Trang 22some operator [z, y, x] of G Q1is then in H2and H2is the subgroup {Q1, H1}.Hence,
Q−p1 P Qp1= RβPα1,(6)
Q−p1 P Qp1 = Rb1Papm−4.(7)
To determine α1 and β we find from (6), (5) and (7)
α1− b1
p
1− bp1(α1− b1)2
o
pm−4
By (1)
Q−p1 2P Qp12 = P,and, therefore,
By (1) and (4)
Q−p1 2R Qp12= P−lp2R Plp2 = R,and, hence,
bp1 ≡ 1 (mod p), ab
p
1− 1
b1− 1 ≡ 0 (mod p),therefore b1= 1
Substituting b1= 1 and α1= 1 + α2pm−5in the congruence determining α1
we obtain (1 + α2pm−5)p≡ 1 (mod pm−3), which gives α2≡ 0 (mod p).Let α2= αp and equations (8) and (7) are now replaced by
Qp1P Qp1= RβP1+αpm−4,(9)
Q−p1 R Qp1= RPapm−4.(10)
Trang 23From these we derive
[−yp, 0, x, yp] =h0, βxy, x +αxy + aβx y
2 + βk x
2y pm−4i,(11)
[−yp, x, 0, yp] = [0, x, axypm−4]
2aβ
n13!s(s − 1)(2s − 1)z
2− 2szo
4 Determination of G
Since H2is self-conjugate in G1 we have
Q−11 P Q1= Qγp1 RδP1,(14)
Q−11 R Q1= Qcp1 RdPepm−4.(15)
From (14), (15) and (13)
[−p, 0, 1, p] = [λp, µ, p1+ vpm−4]and by (9) and (1)
λp ≡ 0 (mod p2), p1+ νpm−4+ λhp ≡ 1 + αpm−4 (mod pm−3),from which
p1≡ 1 (mod p2), and 1≡ 1 (mod p) (m > 5).Let 1= 1 + 2p and equation (14) is replaced by
1acdd
n(dn− 1)
Trang 24(1 + 2p)p− 1
2p2 ≡ 1 (mod p), (2+ γh)p2≡ 0 (mod pm−4)and
[−y, 0, x, y] =hxγy + cδ y
2 p, δxy, x(1 + 2yp) + θpm−4i(20)
where
θ =neδx + aδγx + 2
α +aδ2
xo y2+1
2ac
n13!y(y − 1)(2y − 1)δ
2− y
2δo+αγy + δky + aδxy2+ (acδ2y + acδ) y2 x
2
Trang 25Equations (19) and (20) are replaced by
[−y, x, 0, y] = [cxyp, x, exypm−4]
(22)
[−y, 0, x, y] =hγy + cδ y
2 xp, δxy, x(1 + ypm−5) + θpm−4i(23)
2δex + αcδ x
2
13!s(s − 1)(2s − 1)z
2
− 2sz p
Trang 265 Transformations of the groups Placing y = 1 and x = −1 in (22) weobtain (17) in the form
R−1Q R = Q1−cpP−epm−4
A comparison of the generational equations of the present section with those ofSection 1, shows that groups, in which δ ≡ 0 (mod p), are simply isomorphicwith those in Section 1, so we need consider only those cases in which δ 6≡ 0(mod p)
All groups of this section are given by
Since Rp= 1, Qp2= 1, and Ppm−3 = 1, R0p1= 1, Q0p12 = 1 and P0p1m−3
The forms of these operators are then
P10 = Q0zR0yP0x,
R10 = Q0z0pR0y0P0x0pm−4,
Q01= Q0z00R0y00P0x00pm−5,where dv[x, p] = 1
Since R is not contained in {P }, and Qp is not contained in {R, P } R01 isnot contained in {P10}, and Q0p
[s0z0p, s0y0, s0x0pm−4] = [0, 0, sxpm−4],and
s0y0≡ 0 (mod p), s0z0≡ 0 (mod p)
Trang 27Either y or z is prime to p or s may be taken = 1.
Θ01≡ kx (mod p),(II)
Φ02≡ Φ2 (mod p),(III)
δ0xz00≡ δy0 (mod p),(IV)
Θ02≡ Θ2 (mod p2),(V)
Φ03≡ cz00 (mod p),(VI)
Θ03≡ Θ3 (mod p)
(VII)
Trang 28The necessary and sufficient condition for the simple isomorphism of G and
G0 is, that these congruences be consistent and admit of solution for the nineindeterminants with x, y0, and z00prime to p
A6 divides into two parts
The groups of A6in which δk + γ ≡ 0 (mod p) are simply isomorphic withthe groups of A1and those in which δk + γ 6≡ 0 (mod p) are simply isomorphicwith the groups of A2 The types are given by equations (25), (26) and (27)where the constants have the values given in Table III
Trang 29A detailed analysis of several cases is given below, as a general illustration
of the methods used
A1.The special forms of the congruences for this case are
0xz0 ≡ kx (mod p),(II)
γz00+ δz0 ≡ 0 (mod p),(III)
δ0xz00≡ δy0 (mod p),(IV)
0xz00≡ x (mod p),(V)
cz00≡ 0 (mod p),(VI)
ex ≡ 0 (mod p)
(VII)
Congruence (IV) gives δ 6≡ 0 (mod p), from (II) k can be ≡ 0 or 6≡ 0 (mod p),(III) gives γ ≡ 0 or 6≡ 0, (V) gives 6≡ 0, (VI) and (VII) give c ≡ e ≡ 0 (mod p).Elimination of x, z0and z00between (II), (III) and (V) gives δk+γ ≡ 0 (mod p)
If k ≡ 0, then γ ≡ 0 (mod p) and if k 6≡ 0, then γ 6≡ 0 (mod p)
A2.The congruences for this case are
0xz0+ k0xy0≡ kx (mod p),(II)
γx00+ δz0≡ 0 (mod p),(III)
δ0xz00≡ δy0 (mod p),(IV)
0xz00≡ x (mod p),(V)
cz00≡ 0 (mod p),(VI)
ex ≡ 0 (mod p)
(VII)
Trang 30Congruence (III) gives γ ≡ 0 or 6≡ 0, (IV) gives δ 6≡ 0, (V) 6≡ 0, (VI) and (VII)give c ≡ e ≡ 0 (mod p) Elimination of x, z0, and z00 between (II), (III) and(V) gives
δk + γ ≡ k0δy0 (mod p)from which
δk + γ 6≡ 0 (mod p)
If k ≡ 0, then γ 6≡ 0, and if γ ≡ 0 then k 6≡ 0 (mod p)
Both γ and k can be 6≡ 0 (mod p) provided the above condition is fulfilled
A5.The congruences for this case are
0xz0− e0y0z ≡ kx (mod p),(II)
γz00+ δz0≡ 0 (mod p),(III)
δ0xz00≡ δy0 (mod p),(IV)
0xz00≡ ex (mod p),(V)
cz00≡ 0 (mod p),(VI)
−e0y0z ≡ kx (mod p),(II)
γz00+ δz0 ≡ 0 (mod p),(III)
δ0xz00≡ δy0 (mod p),(IV)
01xz00+ δ0e0x z200 + e0yz00≡ e1x + γx00+ δx0 (mod p),
(V)
cz00≡ 0 (mod p),(VI)
e0y0z00≡ ex (mod p)
(VII)
(II), and (III) being linear in z and z0 give k ≡ 0 or 6≡ 0, and γ ≡ 0 or 6≡ 0(mod p), (IV) gives δ 6≡ 0, (V) being linear in x0 gives 1 ≡ 0 or 6≡ 0 (mod p),(VI) gives c ≡ 0 and (VII) e 6≡ 0
Trang 31Elimination of x and y from (IV) and (VII) gives
Qp1 is contained in the subgroup H1of order pm−2, H1= {Qp1, P }
2 Determination of H1 Since {P } is self-conjugate in H1
R−11 QpR1= Qbp1 Pα1 p.(6)
Using the symbol [a, b, c, d, e, f, · · · ] to denote RaQb
1PcRdQePf· · · , wehave from (5), (6) and (3)
22
Burnside, Theory of Groups, Art 54, p 64.
Trang 32and by (4)
αp1≡ 1 (mod p), and α1≡ 1 (mod p)
Let α1= 1 + α2p and (5) is now replaced by
a1p2(1 + U0p) = a1{1 + (α2+ βh)p}p− 1
(α2+ βh)p2 p2from which
a1p2(1 + U0p) ≡ 0 (mod pm−3)or
N = p and M = βh (1 + α2p)p− 1
α2p2 − 1
,
from which
(1 + α2p)p+(1 + α2p)
p− 1
α2p2 βhp2≡ 1 (mod pm−3)
Trang 33(1 + α2p)p− 1
α2p2 {α2+ βh}p2≡ 0 (mod pm−3)and since
2aβ
h13!s(s − 1)(2s − 1)z
2− s
2zixopm−5.Placing in this y = 0, z = 1 and s = p,23
(R1Px)p= Rp1Pxp= P(x+l)p,determine x so that
x + l ≡ 0 (mod pm−4),then R = R1Pxis an operator of order p which will be used in the place of R1,
Rp= 1
4 Determination of G Since H2 is self-conjugate in G
Q−11 P Q1= RγQδp1 P1,(14)
Q−11 R Q1= RcQdp1 Pe1 p
.(15)
23 Terms of the form (Ax2+ Bx)pm−4in the exponent of P for p = 3 and m > 5 do not alter the result.
Trang 34M = γdp − 1
(1 + 2p)p− 1
2p2and
(2+ δh)p2
[1 + (2+ δh)p]p− 1(2+ δh)p − p
Trang 35
By (1)
(1 + 2p)p+ (N + M h)p2≡ 1 + kpm−4 (mod pm−3),
or reducing
ψ(2+ δh)p2≡ kpm−4 (mod pm−3),where
ψ = (1 + 2p)
p− 1
2p2 + N − e1γp − 1
2 .Since
ψ = 1 (mod p)
From (18), (20), (13), (16) and (21)
[0, −y, x, 0, y] = [γxy, θ1p, x + φ1p],(22)
[0, −y, 0, x, y] = [x, dxyp, φ2p],(23)
2ad
13!y(y − 1)(2y − 1)γ
2aβ
13!x(x − 1)(2x − 1)γ
Q−p1 R Qp1= R,and by (19)
a ≡ 0 (mod p)
A continued multiplication, with (11), (22), and (23), gives
(Q1Px)p2 = Qp12Pxp2 = P(x+l)p2