G = D8xV4 is Direct product D8 x V_4
The Hall-Senior number of this group is 8.
G has 4 minimal generators, rank 4 and exponent 4. The centre has rank 3.
There are 2 conjugacy classes of maximal elementary abelian subgroups. Their ranks are: 4, 4.
This cohomology ring calculation is complete.
Ring structure | Completion information | Koszul information | Restriction information | Poincaré series
The cohomology ring has 5 generators:
There is one minimal relation:
This minimal generating set constitutes a Gröbner basis for the relations ideal.
This cohomology ring was obtained from a calculation out to degree 8. The cohomology ring approximation is stable from degree 2 onwards, and Benson's tests detect stability from degree 4 onwards.
This cohomology ring has dimension 4 and depth 4. Here is a homogeneous system of parameters:
The first 4 terms h1, h2, h3, h4 form a regular sequence of maximum length.
The first 3 terms h1, h2, h3 form a complete Duflot regular sequence. That is, their restrictions to the greatest central elementary abelian subgroup form a regular sequence of maximal length.
Data for Benson's test:
A basis for R/(h1, h2, h3, h4) is as follows.
(1 + 2t + t2) / (1 - t)2 (1 - t2)2