Abstract
We initiate the theory of a quadratic form q over a semiring R, with a view to study tropical linear algebra. As customary, one can writeq(x+y)=q(x)+q(y)+b(x,y), where b is a companion bilinear form. In contrast to the classical theory of quadratic forms over a field, the companion bilinear form need not be uniquely defined. Nevertheless, q can always be written as a sum of quadratic forms q=qQL+ρ, where qQL is quasilinear in the sense that qQL(x+y)=qQL(x)+qQL(y), and ρ is rigid in the sense that it has a unique companion. In case that R is supertropical, we obtain an explicit classification of these decompositions q=qQL+ρ and of all companions b of q, and see how this relates to the tropicalization procedure.
Original language | English |
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Pages (from-to) | 61-93 |
Number of pages | 33 |
Journal | Journal of Pure and Applied Algebra |
Volume | 220 |
Issue number | 1 |
Early online date | 12 Jun 2015 |
DOIs | |
Publication status | Published - 1 Jan 2016 |