Solution 19:The Group of Rigid Motions

Solution 19: The Group of Rigid Motions

Home
Table of Contents
Index

(a)

We have

Then

(b)

(c)

Because , , and are linearly independent, they form a basis for . Every 1-form can be written as a linear combinations of , , and , or . Because is left-invariant, we have

or

Because , , and are linearly independent, then the coefficients of the previous equation must all be zero. Thus

We know that s is a specific motion in M, and this implies that and must all be constants. Thus we have found all 1-forms that are invariant under left translations.

Problem 19

References: Santalo