6 papers · 1 filter
Linear Operators on Polynomials and -Positivity Preserver -- A journey from analysis to algebra and back
Philipp J. di Dio
These are the extended lecture notes of my lecture about ``Linear Operators on Polynomials, -Positivity Preserver, and their Generators''. The lecture was given at the Universit…
Linear Operators and -Positivity Preserver: A Short Review
Philipp J. di Dio
In the current short review we present the latest developments on linear maps , especially of -positivity preserver, i.e…
Characterization of Matrix -Positivity Preserver for and for Compact Sets
Philipp J. di Dio, Lars-Luca Langer
For any closed , in [P.\ J.\ di\,Dio, K.\ Schmüdgen: -Positivity Preserver and their Generators, SIAM J.\ Appl.\ Algebra Geom.\ 9 (2025), 794--824] all…
Absolutely continuous representing measures of complex sequences
Philipp J. di Dio
In 1989, A. J. Duran [Proc. Amer. Math. Soc. 107 (1989), 731-741] showed, that for every complex sequence there exists a Schwartz function $f\in\math…
Absolutely Continuous Representing Measures of Moment Sequences with an Emphasis on the Regularity of the Densities
Philipp J. di Dio
In this work we investigate and characterize linear functionals with absolutely continuous representing measures , i.e., $\mathrm{d}Î…
The Hadamard Product of Moment Sequences, Diagonal Positivity Preservers, and their Generators
Philipp J. di Dio, Lars-Luca Langer
In this work we investigate special aspects of positivity preservers and especially diagonal positivity preservers, i.e., linear maps $T:\mathbb{R}[x_1,\dots,x_n]\to\mathbb{R}[x_1,…