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J. Cimprič

Publications and source records attributed to J. Cimprič.

4 recordsLinked to original sources

Left Jacobson Rings

We say that a ring is strongly (resp. weakly) left Jacobson if every semiprime (resp. prime) left ideal is an intersection of maximal left ideals. There exist Jacobson rings that are not weakly left Jacobson, e.g. the Weyl algebra. Our main result is the following one-sided noncommutative Nullstellensatz: For any finite-dimensional F-algebra A the ring A[$x_1$,...,$x_n$] of polynomials with coefficients in A is strongly left Jacobson and every maximal left ideal of A[$x_1$,...,$x_n$] has finite codimension. We also prove that an Azumaya algebra is strongly left Jacobson iff its center is Jacobson and that an algebra that is a finitely generated module over its center is weakly left Jacobson iff it is Jacobson.

math.RA

Matrix versions of real and quaternionic nullstellensatz

Real Nullstellensatz is a classical result from Real Algebraic Geometry. It has recently been extended to quaternionic polynomials by Alon and Paran. The aim of this paper is to extend their Quaternionic Nullstellensatz to matrix polynomials. We also obtain an improvement of the Real Nullstellensatz for matrix polynomials in the sense that we simplify the definition of a real left ideal. We use the methods from the proof of the matrix version of Hilbert's Nullstellensatz and we obtain their extensions to a mildly non-commutative case and to the real case.

math.RA

Moment problems for operator polynomials

We extend Haviland's theorem on the integral representation of positive linear functionals on usual (real multivariate) polynomials to the integral representation of positive linear maps on operator polynomials mapping into the space of operators. We also extend its special case of compact semialgebraic set studied by Schmüdgen to matrix polynomials and show with a counterexample, that the extension to the operator polynomials fails in general.

math.FA