The exterior algebra is a quotient of the Tensor algebra, with product the Wedge product
It can be defined as
where is the Tensor algebra of and is the Ideal generated by elements of the form where . So consists of all sums of multiples by on the left and right of these generators. We can also see as the kernel of a certain projection map related to Permutations (see wave-notebook..)
Equivalently, we can define (called exterior power) to be the Vector subspace of on which the Symmetric group acts antisymmetrically (see wave-notebook..).
See here and wave-notebook.
If is a basis for , then is a basis for . Hence the dimension of is . It is an associative supercommutative graded -algebra
– The wedge product, exterior power and exterior algebra can be defined for Vector bundles too. The elements of an exterior power of vector bundles are called Exterior forms