Flat extension and ideal projection
نویسنده
چکیده
A generalization of the the flat extension theorems of Curto and Fialkow and Laurent and Mourrain is obtained by seeing the problem as one of ideal projection. Some other results on ideal projection are generalized, and it is seen that a linear functional on the k-variate polynomials over C is finitely atomic if and only if its moment matrix has finite rank, a fact previously known for positive functionals. A characterization of solutions to constant-coefficient difference equations obtained as a corollary.
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