Milnor ring

Milnor ring

In the mathematical discipline known as K-theory, the Milnor ring of a field F, named after John Milnor, is defined [1] as the graded ring  K_*^M (F) with unit, generated by symbols  \ell(a) (for  a \in F -\{0\} of degree one, with relations

 \ell(ab)=\ell(a)+\ell(b),\quad  \ell(a)\ell(1-a)=0. \,

One can show that  K_0^M (F)={\mathbb Z} ,  K_1^M (F)=F -\{0\} .

The Milnor ring appears as one side of the Milnor conjecture.

References

  1. ^ T.A. Springer, A remark on the Milnor ring, Inventiones mathematicae, 1970