Sökning: "Hilbert series"
Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Hilbert series.
1. Around minimal Hilbert series problems for graded algebras
Sammanfattning : The Hilbert series of a graded algebra is an invariant that encodes the dimension of the algebra's graded compontents. It can be seen as a tool for measuring the size of a graded algebra. This gives rise to the idea of algebras with a "minimal Hilbert series", among the algebras within a certain family. LÄS MER
2. Tangential Derivations, Hilbert Series and Modules over Lie Algebroids
Sammanfattning : Let A/k be a local commutative algebra over a field k of characteristic 0, and T_{A/k} be the module of k-linear derivations on A. We study, in two papers, the set of k-linear derivations on A which are tangential to an ideal I of A (preserves I), defining an A-submodule T_{A/k}(I) of T_{A/k}, which moreover is a k-Lie subalgebra. LÄS MER
3. Waring-type problems for polynomials : Algebra meets Geometry
Sammanfattning : In the present thesis we analyze different types of additive decompositions of homogeneous polynomials. These problems are usually called Waring-type problems and their story go back to the mid-19th century and, recently, they received the attention of a large community of mathematicians and engineers due to several applications. LÄS MER
4. Hilbert space frames and bases : a comparison of Gabor and wavelet frames and applications to multicarrier digital communications
Sammanfattning : Several signal processing applications today are based on the use of different transforms. The signals under consideration are written as a linear combination (or series) of some predefined set of functions. Traditionally, orthogonal bases have been used for this purpose, for example, in the discrete Fourier transform. LÄS MER
5. Infinite dimensional holomorphy in the ring of formal power series : partial differential operators
Sammanfattning : We study holomorphy in the ring of formal power series in an infinite number of variables. Thus we restrict our study to (infinite dimensional) holomorphy on sequence spaces and we show that we obtain a rich theory without requiring any topological structure on the domain space. We make a comprehensive PDO-study for the spaces under consideration. LÄS MER