Cayley-Dixon projection operator for multi-univariate composed polynomials

  • Authors:

  • Arthur D. Chtcherba;Deepak Kapur;Manfred Minimair

  • Affiliations:

  • Bloomberg LP, 731 Lexington, New York, NY, USA;University of New Mexico, Department of Computer Science, Albuquerque, NM, USA;Seton Hall University, Department of Mathematics and Computer Science, South Orange, NJ, USA

  • Venue:
  • Journal of Symbolic Computation
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

The Cayley-Dixon formulation for multivariate projection operators (multiples of resultants of multivariate polynomials) has been shown to be efficient (both experimentally and theoretically) for simultaneously eliminating many variables from a polynomial system. In this paper, the behavior of the Cayley-Dixon projection operator and the structure of Dixon matrices are analyzed for composed polynomial systems constructed from a multivariate system in which each variable is substituted by a univariate polynomial in a distinct variable. Under some conditions, it is shown that a Dixon projection operator of the composed system can be expressed as a power of the resultant of the outer polynomial system multiplied by powers of the leading coefficients of the univariate polynomials substituted for variables in the outer system. A new resultant formula is derived for systems where it is known that the Cayley-Dixon construction does not contain any extraneous factor. The complexity of constructing Dixon matrices and roots at toric infinity of composed polynomials is analyzed.