GROUP OF ORDER 64 #85

GROUP #85

The MAGMA library number for G is 71

GrpPC : G of order 64 = 2^6 PC-Relations: G.1^2 = G.4 * G.6, G.2^2 = G.4 * G.6, G.3^2 = G.4, G.2^G.1 = G.2 * G.5, G.3^G.1 = G.3 * G.6, G.3^G.2 = G.3 * G.6

The center of G is abelian of type [ 2, 2, 2 ] .
The orders of the terms of the lower central series are [ 64, 4, 1 ] .
The orders of the terms of the upper central series are [ 1, 8, 64 ] .
The order of the Frattini subgroup is 8.
The exponent of G is 4.
G has 2 conjugacy classes of maximal elementary abelian p-subgroups. The orders of the maximal elementary abelian subgroups are [ 16, 16 ] .
The orders of the centralizers of the maximal elementary abelian subgroups are [ 16, 16 ] .
The orders of the normalizers of the maximal elementary abelian subgroups are [ 64, 64 ] .

The cohomology ring of G is the quotient of a polynomial ring in the variables
[ z, y, x, w, v, u, t ] in degrees [ 1, 1, 1, 2, 2, 2, 2 ] , by the ideal generated by the relations
z2 + y2 + x2 ,
zy ,
zx + yx + x2 ,
zv + yv + xv ,
yx3 + x4 + x2t + v2 .


The Hilbert series for the cohomology ring is
1 / t5 -3t4+ 2t3+ 2t2 -3t+ 1.
Its denominator factors as ( t-1 )4 ( t+1 ) .

The Krull dimension of the cohomology ring is 4.
The longest regular sequence consists of the generators w , u , t .
A homogeneous set of parameters is the set w , u , t , x2 of degrees [ 2, 2, 2, 2 ] .

The hypercohomolgy spectral sequence has E2 term:

ROW (1) : [] [ z+ y+ x ] [ y2+ yx ]
ROW (0) : [1] [ z, y, x ] [ v, y2, yx ] [ yv, xv ] [ yxv ]


Restrictions to Maximal Elementary Abelian Subgroups

Subgroup E #1
Generated by [ G.1 * G.3 * G.5 * G.6, G.4, G.6, G.4 * G.5 ]

The cohomology ring of E is a polynomial ring in the variables z , y , x , w .

The images of the generators of the cohomology of G restricted to E are
z ,
0 ,
z ,
zy + y2 ,
zy + zw ,
zx + x2 ,
z2 + y2 + w2
in the cohomology of E.

The kernel of the restriction to E (Minimal Prime) of the cohomology of G is generated by
z + x ,
y .


Subgroup E #2
Generated by [ G.4, G.6, G.2 * G.3 * G.4 * G.5 * G.6, G.4 * G.5 ]

The cohomology ring of E is a polynomial ring in the variables z , y , x , w .

The images of the generators of the cohomology of G restricted to E are
0 ,
z ,
z ,
zy + y2 ,
zy + zw ,
z2 + zx + x2 ,
y2 + w2
in the cohomology of E.

The kernel of the restriction to E (Minimal Prime) of the cohomology of G is generated by
z ,
y + x .


The nilradical of the cohomology of G is generated by
z + y + x

It is nilpotent of degree 2.


Restrictions to Maximal Subgroups

Maximal Subgroup H #1 Generated by [ G.1, G.4, G.5, G.6, G.2 * G.3 * G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number11 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.3, $.2^$.1 = $.2 * $.5 Generated by [ G.1 * G.2 * G.3 * G.4, G.2 * G.3 * G.4 * G.6, G.6 ]

of type Cyclic(2) x Group(16)#9 .

The images of the generators of the cohomology of G restricted to H are
z ,
z + y ,
z + y ,
w + v + u ,
zx + w ,
y2 + zx + yx + x2 + u ,
v
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
y + x .


Maximal Subgroup H #2 Generated by [ G.3, G.2, G.4, G.5, G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number11 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.3, $.2^$.1 = $.2 * $.5 Generated by [ G.5, G.3 * G.5, G.2 * G.3 * G.4 * G.5 * G.6 ]

of type Cyclic(2) x Group(16)#9 .

The images of the generators of the cohomology of G restricted to H are
0 ,
y ,
z + y ,
yx + x2 ,
w ,
y2 + u ,
v
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
z .


Maximal Subgroup H #3 Generated by [ G.3, G.1 * G.2, G.4, G.5, G.6 ] .

The group H is abelian of type [ 4, 4, 2 ]

The cohomology ring of H is a the quotient of a polynomial ring in the variables
[ z, y, x, w, v ] , in degrees [ 1, 1, 1, 2, 2 ] , by the ideal of relations
z2 , y2 .

The images of the generators of the cohomology of G restricted to H are
y ,
y ,
z ,
v ,
zx ,
zx + x2 ,
w
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
z + y .


Maximal Subgroup H #4 Generated by [ G.1 * G.2, G.4, G.5, G.6, G.2 * G.3 * G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number8 GrpPC of order 32 = 2^5 PC-Relations: $.3^$.1 = $.3 * $.5, $.3^$.2 = $.3 * $.5, $.4^$.3 = $.4 * $.5 Generated by [ G.1 * G.3 * G.5 * G.6, G.2 * G.3 * G.4 * G.6, G.2 * G.3 * G.4, G.2 * G.3 * G.6 ]

of type Abelian(2,2) x Dihedral(8) .

The images of the generators of the cohomology of G restricted to H are
x ,
z + y + w ,
z + y + x + w ,
v ,
zw + yw + xw + w2 ,
z2 + zy + y2 + zx + yw + xw + w2 ,
x2 + w2
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
z + y + x .


Maximal Subgroup H #5 Generated by [ G.2, G.4, G.5, G.6, G.1 * G.3 * G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number11 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.3, $.2^$.1 = $.2 * $.5 Generated by [ G.6, G.1 * G.2 * G.3 * G.4 * G.5, G.1 * G.3 * G.4 * G.6 ]

of type Cyclic(2) x Group(16)#9 .

The images of the generators of the cohomology of G restricted to H are
z + y ,
z ,
z + y ,
w + v + u ,
y2 + zx + w ,
zx + yx + x2 + u ,
v
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
z + x .


Maximal Subgroup H #6 Generated by [ G.1, G.2, G.4, G.5, G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number12 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4, $.2^2 = $.5, $.3^2 = $.5, $.2^$.1 = $.2 * $.5, $.3^$.1 = $.3 * $.5 Generated by [ G.1 * G.2 * G.5, G.2 * G.6, G.1 * G.2 * G.5 * G.6 ]

of type Cyclic(2) x Group(16)#10 .

The images of the generators of the cohomology of G restricted to H are
y + x ,
z + y + x ,
0 ,
zy + v ,
zy ,
zy + y2 + zx + w ,
zy + zx + w
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
x .


Maximal Subgroup H #7 Generated by [ G.1, G.3, G.4, G.5, G.6 ] .

The Group H is Isomorphic to the Group of Order 32 Number11 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.3, $.2^$.1 = $.2 * $.5 Generated by [ G.1 * G.3 * G.4 * G.5 * G.6, G.5, G.3 * G.5 ]

of type Cyclic(2) x Group(16)#9 .

The images of the generators of the cohomology of G restricted to H are
y ,
0 ,
z + y ,
yx + x2 ,
y2 + w ,
u ,
v
in the cohomology of H.

The kernel of the restriction to H of the cohomology of G is generated by
y .


The essential cohomology of G is zero.



Inflations from Maximal Quotient Groups

Maximal Quotient Group Q #1.

The kernel of the quotient is generated by G.4 * G.6 .

The Group Q is Isomorphic to the Group of Order 32 Number34 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4, $.3^2 = $.5, $.2^$.1 = $.2 * $.4, $.3^$.2 = $.3 * $.5 .

The generators of G have images [ pcy.3, pcy.2, pcy.1 * pcy.2 * pcy.4 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
z ,
z + y ,
x ,
z2 + w ,
z2 + y2 + v + u + t
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
y2 + x2 .



Maximal Quotient Group Q #2.

The kernel of the quotient is generated by G.5 .

The Group Q is Isomorphic to the Group of Order 32 Number11 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.3, $.2^$.1 = $.2 * $.5

of type Cyclic(2) x Group(16)#9 .

The generators of G have images [ pcy.1 * pcy.4, pcy.1 * pcy.2, pcy.1 * pcy.2 * pcy.4 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
z + y + x ,
z + y ,
z + x ,
z2 + y2 + yx + v ,
t ,
yx + u
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
yx + x2 .



Maximal Quotient Group Q #3.

The kernel of the quotient is generated by G.4 * G.5 * G.6 .

The Group Q is Isomorphic to the Group of Order 32 Number39 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4 * $.5, $.2^2 = $.5, $.3^2 = $.5, $.2^$.1 = $.2 * $.4, $.3^$.2 = $.3 * $.5 .

The generators of G have images [ pcy.1 * pcy.3 * pcy.4 * pcy.5, pcy.2, pcy.2 * pcy.3 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
x ,
z + y ,
z + x ,
v + u + t ,
y2x + xw + xu ,
z2w + y2w + zxu + yxu + w2 + u2
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
yx + x2 .



Maximal Quotient Group Q #4.

The kernel of the quotient is generated by G.5 * G.6 .

The Group Q is Isomorphic to the Group of Order 32 Number14 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4 * $.5, $.2^2 = $.4, $.2^$.1 = $.2 * $.5, $.3^$.2 = $.3 * $.5

of type Cyclic(4) x Dihedral(8) .

The generators of G have images [ pcy.2 * pcy.4 * pcy.5, pcy.2 * pcy.3 * pcy.5, pcy.1 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
z ,
y + x ,
y ,
z2 + y2 + t ,
w + v + u
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
zx .



Maximal Quotient Group Q #5.

The kernel of the quotient is generated by G.4 * G.5 .

The Group Q is Isomorphic to the Group of Order 32 Number36 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4, $.2^2 = $.4 * $.5, $.3^2 = $.4, $.2^$.1 = $.2 * $.4, $.3^$.2 = $.3 * $.5 .

The generators of G have images [ pcy.3, pcy.1 * pcy.2 * pcy.4, pcy.2 * pcy.4 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
y ,
z + y ,
x ,
z2 + y2 + yx + u ,
z2 + yx + w + v + t
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
yx + x2 .



Maximal Quotient Group Q #6.

The kernel of the quotient is generated by G.6 .

The Group Q is Isomorphic to the Group of Order 32 Number14 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4 * $.5, $.2^2 = $.4, $.2^$.1 = $.2 * $.5, $.3^$.2 = $.3 * $.5

of type Cyclic(4) x Dihedral(8) .

The generators of G have images [ pcy.1 * pcy.3 * pcy.4 * pcy.5, pcy.1 * pcy.4, pcy.2 * pcy.3 * pcy.5 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
y + x ,
z ,
z + x ,
z2 + t ,
z2 + w + t
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
zx .



Maximal Quotient Group Q #7.

The kernel of the quotient is generated by G.4 .

The Group Q is Isomorphic to the Group of Order 32 Number36 GrpPC of order 32 = 2^5 PC-Relations: $.1^2 = $.4, $.2^2 = $.4 * $.5, $.3^2 = $.4, $.2^$.1 = $.2 * $.4, $.3^$.2 = $.3 * $.5 .

The generators of G have images [ pcy.1 * pcy.3 * pcy.4, pcy.2, pcy.1 * pcy.2 * pcy.4 ] in the quotient group.

The images of the generators of the cohomology of Q inflated to G are
z + x ,
z + y ,
x ,
z2 + y2 + yx + u ,
y2 + yx + w + u
in the cohomology of G.

The kernel of the inflation to G of the cohomology of Q is generated by
yx + x2 .



The depth-essential cohomology of G

The depth-essential cohomology of G is the intersection of the restrictions to the centralizers of the maximal elementary abelian p-subgroups of rank d+1 where d is the depth of the cohomology ring. For this group the depth is 3.



There are 2 conjugacy classes of subgroups which are centralizers of elementary abelian subgroups of rank 4. They are represented by the subgroups generated by


[ G.1 * G.3 * G.5 * G.6, G.1 * G.3 * G.4 * G.5 * G.6, G.1 * G.3 * G.5, G.1 * G.3 * G.4 * G.6 ]
[ G.2 * G.3 * G.5, G.2 * G.3 * G.4 * G.6, G.2 * G.3 * G.4, G.2 * G.3 * G.4 * G.5 * G.6 ] .

The depth-essential cohomology of G is generated as an ideal by
z + y + x .

The annihilator of the depth-essential cohomology has dimension 3 .

The depth-essential cohomology is a free module over the polynomial subring Q of the cohomology ring of G generated by w , u , t .
The depth-essential cohomology is generated as a module over Q by the elements
[ z+ y+ x ] [ y2+ yx ]



Action of Automorphisms

The groups of outer automorphisms of G has order 256, and is generated by 8 elements.

Automorphism #1

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
z2 + y2 + v ,
u ,
z2 + y2 + t .

Automorphism #2

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
v ,
u ,
t .

Automorphism #3

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
z2 + y2 + v ,
u ,
z2 + y2 + t .

Automorphism #4

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
y2 + yx + v ,
y2 + yx + u ,
t .

Automorphism #5

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
v ,
u ,
t .

Automorphism #6

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z ,
y ,
x ,
w ,
z2 + y2 + yx + v ,
y2 + yx + u ,
z2 + t .

Automorphism #7

The order of the class of the automorphism in the outer automorphism group is 2. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
y ,
z ,
x ,
w ,
z2 + y2 + v ,
z2 + y2 + u ,
t .

Automorphism #8

The order of the class of the automorphism in the outer automorphism group is 4. The images of the generators of G are

The images of the generators of the cohomology of G under the map induced by the automorphism are
z + x ,
y + x ,
x ,
z2 + y2 + w + v + u + t ,
z2 + y2 + v ,
z2 + y2 + u ,
t .


CHECKS

paramflag = true
qregflagflag = true
cmflag = false
essflag = true
centflag = true

THE COMPUTATION IS COMPLETE