Observations on interpolation by total degree polynomials in two variables
For researchers in multivariate polynomial interpolation, this provides algebraic insights into known constructions, but the results are incremental.
The paper studies algebraic properties of two interpolation configurations (Radon-Berzolari and Chung-Yao) for total degree polynomials in two variables, deriving properties of syzygy matrices to understand point geometry.
In contrast to the univariate case, interpolation with polynomials of a given maximal total degree is not always possible even if the number of interpolation points and the space dimension coincide. Due to that, numerous constructions for interpolation sets have been devised, the most popular ones being based on intersections of lines. In this paper, we study algebraic properties of some such interpolation configurations, namely the approaches by Radon-Berzolari and Chung-Yao. By means of proper H-bases for the vanishing ideal of the configuration, we derive properties of the matrix of first syzygies of this ideal which allow us to draw conclusions on the geometry of the point configuration.