A Sagbi Basis For

A new algorithm for computing SAGBI bases up to an arbitrary degree

We present a new algorithm for computing a SAGBI basis up to an arbitrary degree for a subalgebra generated by a set of homogeneous polynomials. Our idea is based on linear algebra methods which cause a low level of complexity and computational cost. We then use it to solve the membership problem in subalgebras.

Sagbi Bases for Rings of Invariant Laurent Polynomials

Let k be a field, Ln = k[x ±1 1 , . . . , x ±1 n ] be the Laurent polynomial ring in n variables and G be a group of k-algebra automorphisms of Ln. We give a necessary and sufficient condition for the ring of invariants Ln to have a SAGBI basis. We show that if this condition is satisfied then Ln has a SAGBI basis relative to any choice of coordinates in Ln and any term order.

Optimal Lower Bound for Generators of Invariant Rings without Finite SAGBI Bases with Respect to Any Admissible Order

)( was investigated. It turned out that only invariant rings of direct products of symmetric groups have a finite SAGBI basis, which is then, in addition, multilinear. Of course, it would be of interest to have such a strong characterization with respect to any other admissible order [4, 6]. To achieve this seems to be all but trivial. One step towards the understanding of the behavior of SAGBI...

SAGBI and SAGBI-Gröbner Bases over Principal Ideal Domains

SAGBI Bases Under Composition

Our interest in the subject of this paper is inspired by Hong (1998), where Hoon Hong addresses the problem of the behavior of Gröbner bases under composition of polynomials. More precisely, let Θ be a set of polynomials, as many as the variables in our polynomial ring. The question then is under which conditions on these polynomials it is true that for an arbitrary Gröbner basis G (with respec...