Lower bounds for norms of products of polynomials via Bombieri inequality
In this paper we give a different interpretation of Bombieri´s norm. This new point of view allows us to work on a problem posed by Beauzamy about the behavior of the sequence $S_n(P)=sup_{Q_n}, [PQ_n]_2$, where $P$ is a fixed $m-$homogeneous polynomial and $Q_n$ runs over the unit ball of the Hilbe...
| Autor: | |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/196933 |
| Acceso en línea: | http://hdl.handle.net/11336/196933 |
| Access Level: | acceso abierto |
| Palabra clave: | BOMBIERI'S INEQUALITY BOMBIERI'S NORM GAUSSIAN MEASURE PLANK PROBLEM POLYNOMIAL PRODUCTS OF LINEAR FUNCTIONALS UNIFORM NORMS INEQUALITIES https://purl.org/becyt/ford/1.1 https://purl.org/becyt/ford/1 |
| Sumario: | In this paper we give a different interpretation of Bombieri´s norm. This new point of view allows us to work on a problem posed by Beauzamy about the behavior of the sequence $S_n(P)=sup_{Q_n}, [PQ_n]_2$, where $P$ is a fixed $m-$homogeneous polynomial and $Q_n$ runs over the unit ball of the Hilbert space of $n-$homogeneous polynomials. We also study the factor problem for homogeneous polynomials defined on $zC^N$ and we obtain sharp inequalities whenever the number of factors is no greater than $N$. In particular, we prove that for the product of homogeneous polynomials on infinite dimensional complex Hilbert spaces our inequality is sharp. Finally, we use these ideas to prove that any set ${z_k}_{k=1}^n$ of unit vectors in a complex Hilbert space for which $sup_{Vert z Vert=1} vert langle z, z_1 angle cdots langle z, z_n angle vert$ is minimum must be an orthonormal system. |
|---|