Equivalence of norms via semi-inner products

A semi-inner product is an “inner-product like” construction that is not necessarily symmetric. In this talk, I will introduce a notion of equivalence for norms, constructed using semi-inner products, which is referred to as angular equivalence. Unlike the usual norm equivalence, angular equivalence preserves (some) geometrical properties of the norms. I will discuss such properties and also answer the question whether the dual norms of two angularly equivalent norms are again angularly equivalent.