Zobrazeno 1 - 10
of 23
pro vyhledávání: '"Pería, Francisco Martínez"'
A quadratically constrained quadratic programming problem is considered in a Hilbert space setting, where neither the objective nor the constraint are convex functions. Necessary and sufficient conditions are provided to guarantee that the problem ad
Externí odkaz:
http://arxiv.org/abs/2303.05204
The relationship between linear relations and matrix pencils is investigated. Given a linear relation, we introduce its Weyr characteristic. If the linear relation is the range (or the kernel) representation of a given matrix pencil, we show that the
Externí odkaz:
http://arxiv.org/abs/2203.08296
An abstract indefinite least squares problem with a quadratic constraint is considered. This is a quadratic programming problem with one quadratic equality constraint, where neither the objective nor the constraint are convex functions. Necessary and
Externí odkaz:
http://arxiv.org/abs/2201.02442
Given bounded selfadjoint operators $A$ and $B$ acting on a Hilbert space $\mathcal{H}$, consider the linear pencil $P(\lambda)=A+\lambda B$, $\lambda\in\mathbb{R}$. The set of parameters $\lambda$ such that $P(\lambda)$ is a positive (semi)definite
Externí odkaz:
http://arxiv.org/abs/2201.02439
Along this work we study an indefinite abstract smoothing problem. After establishing necessary and sufficient conditions for the existence of solutions to this problem, the set of admissible parameters is discussed in detail. Then, its relationship
Externí odkaz:
http://arxiv.org/abs/2008.03491
Autor:
Giribet, Juan, Langer, Matthias, Pería, Francisco Martínez, Philipp, Friedrich, Trunk, Carsten
Publikováno v:
Journal of Functional Analysis 278 (2020), 108455, 30pp
We prove new spectral enclosures for the non-real spectrum of a class of $2\times2$ block operator matrices with self-adjoint operators $A$ and $D$ on the diagonal and operators $B$ and $-B^*$ as off-diagonal entries. One of our main results resemble
Externí odkaz:
http://arxiv.org/abs/1903.01519
Given a positive definite matrix $A\in \mathbb{C}^{n\times n}$ and a Hermitian matrix $D\in \mathbb{C}^{m\times m}$, we characterize under which conditions there exists a strictly contractive matrix $K\in \mathbb{C}^{n\times m}$ such that the non-Her
Externí odkaz:
http://arxiv.org/abs/1807.08591
A $J$-frame for a Krein space $\mathcal{H}$ is in particular a frame for $\mathcal{H}$ (in the Hilbert space sense). But it is also compatible with the indefinite inner-product of $\mathcal{H}$, meaning that it determines a pair of maximal uniformly
Externí odkaz:
http://arxiv.org/abs/1703.03660
Autor:
Giribet, Juan Ignacio, Langer, Matthias, Leben, Leslie, Maestripieri, Alejandra, Pería, Francisco Martínez, Trunk, Carsten
Publikováno v:
Opuscula Math. 38 (2018), 623-649
A $J$-frame is a frame $\mathcal{F}$ for a Krein space $(\mathcal{H}, [\, , \,])$ which is compatible with the indefinite inner product $[\, , \, ]$ in the sense that it induces an indefinite reconstruction formula that resembles those produced by or
Externí odkaz:
http://arxiv.org/abs/1703.03665
Let $\mathcal{H}$ be a Krein space with fundamental symmetry $J$. Along this paper, the geometric structure of the set of $J$-normal projections $\mathcal{Q}$ is studied. The group of $J$-unitary operators $\mathcal{U}_J$ naturally acts on $\mathcal{
Externí odkaz:
http://arxiv.org/abs/1504.04253