GROUP OF ORDER 16 # 6

GROUP OF ORDER 16 # 6

Cyclic(2) x Dihedral(8)

The MAGMA library number for G is 11

GrpPC : G of order 16 = 2^4 PC-Relations: G.3^2 = G.4, G.2^G.1 = G.2 * G.4, G.3^G.1 = G.3 * G.4, G.3^G.2 = G.3 * G.4

The center of G is abelian of type [ 2, 2 ]
The orders of the terms of the lower central series are [ 16, 2, 1 ]
The orders of the terms of the upper central series are [ 1, 4, 16 ]
The order of the Frattini subgroup is 2
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 [ 8, 8 ]
The orders of the centralizers of the maximal elementary abelian subgroups are [ 8, 8 ]
The orders of the normalizers of the maximal elementary abelian subgroups are [ 16, 16 ]

The cohomology ring of G is the quotient of a polynomial ring in the variables [ z, y, x, w ] in degrees [ 1, 1, 1, 2 ] by the ideal generated by the relations
[ z*y + z*x + y*x + x^2 ]

The Hilbert series for the cohomology ring is -1/(t^3 - 3*t^2 + 3*t - 1)
Its denominator factors as ( t - 1 )^3

The Krull dimension of the cohomology ring is 3
The cohomology ring is Cohen-Macaulay and the longest regular sequence consists of the generators [ z^2, y^2, w ]

Restrictions to Maximal Elementary Abelian Subgroups

Subgroup E # 1
Generated by [ G.1 * G.2 * G.3 * G.4, G.1 * G.2 * G.3, G.2 * G.3 ]

The cohomology ring of E is a polynomial ring in the variables [ z, y, x ]

The images of the generators of the cohomology of G restricted to E are
[ y + x, z + y + x, z + y + x, z*x + x^2 ] in the cohomology of E

The kernel of the restriction to E (Minimal Prime) of the cohomology of G is generated by
[ y + x ]

Subgroup E # 2
Generated by [ G.1 * G.2 * G.3 * G.4, G.1 * G.3, G.1 * G.2 * G.3 ]

The cohomology ring of E is a polynomial ring in the variables [ z, y, x ]

The images of the generators of the cohomology of G restricted to E are
[ z + y + x, y + x, z + y + x, z*x + x^2 ] in the cohomology of E

The kernel of the restriction to E (Minimal Prime) of the cohomology of G is generated by
[ z + x ]

The nilradical of the cohomology of G is zero

Restrictions to Maximal Subgroups

Maximal Subgroup H # 1

The Group H is Isomorphic to the Group of Order 8 Number 4 GrpPC of order 8 = 2^3 PC-Relations: $.2^2 = $.3, $.2^$.1 = $.2 * $.3 Generated by [ G.3, G.2 ]

of type Dihedral(8)

The images of the generators of the cohomology of G restricted to H are
[ 0, z, y, x ] in the cohomology of H

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

Maximal Subgroup H # 2

The Group H is Isomorphic to the Group of Order 8 Number 4 GrpPC of order 8 = 2^3 PC-Relations: $.2^2 = $.3, $.2^$.1 = $.2 * $.3 Generated by [ G.1 * G.2 * G.4, G.1 ]

of type Dihedral(8)

The images of the generators of the cohomology of G restricted to H are
[ z + y, y, 0, x ] in the cohomology of H

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

Maximal Subgroup H # 3

The Group H is Isomorphic to the Group of Order 8 Number 4 GrpPC of order 8 = 2^3 PC-Relations: $.2^2 = $.3, $.2^$.1 = $.2 * $.3 Generated by [ G.1 * G.2 * G.4, G.1 * G.3 ]

of type Dihedral(8)

The images of the generators of the cohomology of G restricted to H are
[ z + y, y, z, x ] 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 # 4

The Group H is Isomorphic to the Group of Order 8 Number 4 GrpPC of order 8 = 2^3 PC-Relations: $.2^2 = $.3, $.2^$.1 = $.2 * $.3 Generated by [ G.3, G.1 ]

of type Dihedral(8)

The images of the generators of the cohomology of G restricted to H are
[ z, 0, y, x ] in the cohomology of H

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

Maximal Subgroup H # 5

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

The cohomology ring of H is a polynomial ring with variables [ z, y, x ] in degrees [ 1, 1, 1 ]

The images of the generators of the cohomology of G restricted to H are
[ z, y, y, z*x + y*x + x^2 ] 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 # 6

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

The cohomology ring of H is a polynomial ring with variables [ z, y, x ] in degrees [ 1, 1, 1 ]

The images of the generators of the cohomology of G restricted to H are
[ z, y, z, z*y + z*x + y*x + x^2 ] 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 # 7

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

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

The images of the generators of the cohomology of G restricted to H are
[ z + y, z + y, y, y^2 + x ] in the cohomology of H

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

The essential cohomology of G is zero

CHECKS

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

THE COMPUTATION IS COMPLETE