Direct product of groups

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created: 2021-12-06 10:48:24
modified: 2022-01-10 04:13:03

and groups.
is the direct product of these groups. It is a group if we define the product of its elements this way:

With set notation:

Simplified notation

The groups are and and their product is .

Element factorization

Every element in the product group can be factorized the following way:

Useful identification

We can use the following identifications: and . With this, the element can be written simplified:

It is easy to see that any and commutes.

Remark

Intuitively, and are two independently operating groups, acting on two independent degrees of freedom. This is why they are commutative.