Why is the exterior algebra called the "exterior algebra?" What makes it "exterior?"

2.1k Views Asked by At

Why is the exterior algebra called the "exterior algebra?" What makes it "exterior?" Is it just because a module can be universally embedded into its exterior algebra, so one could view the exterior algebra as surrounding the module? Why is it not just called the "alternating algebra?"

1

There are 1 best solutions below

1
On BEST ANSWER

It was Grassmann that called it exterior because to have a non-null product the multiplicands must be geometrically one to the exterior of the other. For instance $$\mathbf{x}\wedge\mathbf{y}\wedge\mathbf{z}=0$$ if $\mathbf{x}$ lies in (is not exterior of) the subspace spanned by the $\mathbf{y}$ and $\mathbf{z}$. So the product is called exterior product, and consequently the algebra with this product is called exterior algebra.