Abstract We define a Toledo number for actions of surface groups and complex hyperbolic lattices on infinite-dimensional Hermitian symmetric spaces, which allows us to maximal representations. When the target is not tube type, we show that there cannot be Zariski-dense representations, whenever existence boundary map can guaranteed, representation preserves finite-dimensional totally geodesic s...

 In network code setting, a constant dimension code is a set of k-dimensional subspaces of F nq . If F_q n is a nondegenerated symlectic vector space with bilinear form f, an isotropic subspace U of F n q is a subspace that for all x, y ∈ U, f(x, y) = 0. We introduce isotropic subspace codes simply as a set of isotropic subspaces and show how the isotropic property use in decoding process, then...

We consider the Cauchy problem for the weakly dissipative wave equation u+ μ 1 + t ut = 0 with parameter μ ≥ 2. Based on the explicit representations of solutions provided in [Math. Meth. Appl. Sci. 2004; 27:101-124] sharp decay estimates for data from a dense subspace of the energy space are derived. Furthermore, sharpness is discussed in terms of a modified scattering theory. AMS subject clas...

In this paper, we present preliminary results on a complete eigensolver based on the Yau and Lu method. We rst give an overview of this invariant subspace decomposition method for dense symmetric matrices followed by numerical results and work in progress of a distributed-memory implementation. We expect that the algorithm's heavy reliance on matrix-matrix multiplication, coupled with FFT shoul...

Let E a C( AT) be a subspace of continuous functions defined on a compact Hausdorff space K. We characterize those spaces for which the rational functions with denominators and numerators from E are dense. Despite the non-linear structure of rational functions, this characterization uses only methods from linear functional analysis. As special cases, we recover various results on the density of...

For a given integer d, 1 ≤ d ≤ n − 1, let Ω be a subset of the set of all d × n real matrices. Define the subspace M(Ω) = span{g(Ax) : A ∈ Ω, g ∈ C(IR, IR)} . We give necessary and sufficient conditions on Ω so that M(Ω) is dense in C(IR, IR) in the topology of uniform convergence on compact subsets. This generalizes work of Vostrecov and Kreines. We also consider some related problems. §

For a metrizable space $X$, we denote by $\mathrm{Met}(X)$ the of all metric that generate same topology $X$. The is equipped with supremum distance. In this paper, for every strongly zero-dimensional prove set metrics whose ranges are closed totally disconnected subsets line dense $G_{\delta}$ subspace in $\mathrm{Met}(X)$. As its application, show some sets universal meager spaces metrics.

In this work we consider the solution of the linear systems arising from electromagentism applications by preconditioned Krylov subspace methods [3]. Simulation of electromagnetic wave propagation phenomena requires the numerical solution of Maxwell’s equations which it is often done by means of integral equation methods. The discretization of the integral equations with the boundary element me...

We provide a careful treatment of the weak Hardy spaces Hp,∞(Rn) for all indices 0 < p < ∞. The study of these spaces presents differences from the study of the Hardy-Lorentz spaces H(R) for q <∞, due to the lack of a good dense subspace of them. We obtain several properties of weak Hardy spaces and we discuss a new square function characterization for them, obtained by He [16].

In this paper we study the space of natural images locally. We apply the techniques of computational algebraic topology to the space of 3x3 and 5x5 high-contrast patches and show that in both cases, the subspace of linear and quadratic gradient patches, which forms a dense subset inside the space of all high-contrast patches, possesses an interesting topological filtration and is itself topolog...