Rees decomposition

In commutative algebra, a Rees decomposition is a way of writing a ring in terms of polynomial subrings. They were introduced by {{harvs|txt|last=Rees|first=David|authorlink=David Rees (mathematician)|year=1956}}.

Definition

Suppose that a ring R is a quotient of a polynomial ring k[x1,...] over a field by some homogeneous ideal. A Rees decomposition of R is a representation of R as a direct sum (of vector spaces)

: R = \bigoplus_\alpha \eta_\alpha k[\theta_1,\ldots,\theta_{f_\alpha}]

where each ηα is a homogeneous element and the d elements θi are a homogeneous system of parameters for R and

ηαk[θfα+1,...,θd] ⊆ k[θ1, θfα].

See also

References

  • {{citation|mr=0074372

|last=Rees|first= D.

|title=A basis theorem for polynomial modules

|journal=Proc. Cambridge Philos. Soc.|volume= 52 |year=1956|pages= 12–16}}

  • {{citation|mr=1122013

|last=Sturmfels|first= Bernd|last2= White|first2= Neil

|title=Computing combinatorial decompositions of rings

|journal=Combinatorica |volume=11 |year=1991|issue= 3|pages= 275–293|doi=10.1007/BF01205079}}

Category:Commutative algebra

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