Multilinear map

Bilinear form

A bilinear form 𝐡 :𝑉 ×𝑉 →𝕂 is a multilinear map from a vector space 𝑉 to its underlying field 𝕂, linalg i.e. linear in both arguments separately

𝐡(𝛼𝑒+𝛽𝑣,𝑀)=𝛼𝐡(𝑒,𝑀)+𝛽𝐡(𝑣,𝑀)𝐡(𝑒,𝛼𝑣+𝛽𝑀)=𝛼𝐡(𝑒,𝑣)+𝛽𝐡(𝑒,𝑀)

Further terminology

  • A bilinear form is called symmetric iff 𝐡(π‘₯,𝑦) =𝐡(𝑦,π‘₯).
  • A bilinear form is called nondegenerate iff 𝑉 β†’π‘‰βˆ— :𝑣 ↦𝐡(𝑣, βˆ’) is an isomorphism, equivalently 𝐡(𝑣,𝑀) =0 for all 𝑀 βˆˆπ‘‰ implies 𝑣 =0.

Properties

See also


tidy | en | SemBr