Source: wikibot/indefinite-inner-product-space
= Indefinite inner product space
{wiki=Indefinite_inner_product_space}
An indefinite inner product space is a vector space equipped with a bilinear (or sesquilinear) form, which is called an inner product, that allows for both positive and negative values. This type of inner product distinguishes itself from the more common inner product spaces that have definite inner products, where the inner product is always non-negative.