Determinants and Multilinear Forms
Stub. The determinant built two ways — inductively via cofactor expansion, and axiomatically as the alternating n-linear form on the columns/rows — plus bilinear and quadratic forms, and tensor products of vector spaces.
Two routes to the same object. The computational route (Friedberg–Insel– Spence): determinants of order 2, then order by cofactor expansion, their properties (multiplicativity, effect of row operations), and a summary characterization. The structural route (Axler): first build general bilinear/quadratic forms and general alternating multilinear forms, then show the determinant is the alternating -linear form on normalized at the identity — which is also the natural setting to introduce tensor products of vector spaces.
Outline (TODO — flesh out each)
- Determinants of order 2, and of order (cofactor expansion)
- Properties of determinants; summary of important facts
- A characterization of the determinant
- Bilinear forms and symmetric bilinear forms; quadratic forms
- Alternating multilinear forms and permutations
- Defining and constructing the determinant as an alternating form
- Tensor products — of two vector spaces, of inner product spaces, of multiple vector spaces