Kaique Roberto - Instituto de Matemática e Estatística, Universidade de Sao Paulo, Brazil.
Hugo Mariano - Instituto de Matemática e Estatística, Universidade de Sao Paulo, Brazil.

We build on previous work on multirings ([۱۷]) that providesgeneralizations of the available abstract quadratic forms theories (specialgroups and real semigroups) to the context of multirings ([۱۰], [۱۴]). Herewe raise one step in this generalization, introducing the concept of pre-specialhyperfields and expand a fundamental tool in quadratic forms theory to themore general multivalued setting: the K-theory. We introduce and developthe K-theory of hyperbolic hyperfields that generalize simultaneously Milnor’sK-theory ([۱۱]) and Special Groups K-theory, developed by Dickmann-Miraglia ([۵]). We develop some properties of this generalized K-theory, thatcan be seen as a free inductive graded ring, a concept introduced in [۲] inorder to provide a solution of Marshall’s Signature Conjecture.

quadratic forms, special groups, K-theory, multirings, hyperfields