We prove that if G is a non-uniform lattice in a rank-one semisimple Lie group = Isom(H2 R ), then G is quasi-isometrically co-Hopf. This means that every quasi-isometric embedding G → G is coarsely surjective and thus is a quasi-isometry.

This paper describes techniques for obtaining high accuracy estimates, including those of non-stationarity, of parameters for sinusoidal modelling using a single frame of analysis data. In this case the data used is generated from the time and frequency reassigned short-time Fourier transform (STFT). Such a system offers the potential for quasi real-time (frame-by-frame) spectral modelling of a...

Energy is in general not conserved for mechanical nonholonomic systems with affine constraints. In this article we point out that, nevertheless, in certain cases, there is a modification of the energy that is conserved. Such a function coincides with the energy of the system relative to a different reference frame, in which the constraint is linear. After giving sufficient conditions for this t...

In this article, we analyze a fully discrete $\varepsilon-$uniformly convergent finite element method for singularly perturbed convection-diffusion-reaction boundary-value problems, on piecewise-uniform meshes. Here, choose $L-$splines as basis functions. We will concentrate the convergence analysis of which employ $L-$spline functions instead their continuous counterparts. The are approximated...

In 1964, Erdős proved that for any α > 0, an l-uniform hypergraph G with n > n0(α, l) vertices and α ( n l ) edges contains a large complete l-equipartite subgraph. This implies that any sufficiently large G with density α > 0 contains a large subgraph with density at least l!/ll. In this note we study a similar problem for l-uniform hypergraphs Q with a weak quasi-random property (i.e. with ed...

We study the efficient numerical solution of infinite matrix equations Au = f for a matrix A in the Jaffard algebra. These matrices appear naturally via frame discretizations in many applications such as Gabor analysis, sampling theory, and quasi-diagonalization of pseudo-differential operators in the weighted Sjöstrand class. The proposed algorithm has two main features: firstly, it converges ...

Chvátal, Rödl, Szemerédi and Trotter [3] proved that the Ramsey numbers of graphs of bounded maximum degree are linear in their order. In [5, 19] the same result was proved for 3-uniform hypergraphs. Here we extend this result to k-uniform hypergraphs for any integer k ≥ 3. As in the 3-uniform case, the main new tool which we prove and use is an embedding lemma for k-uniform hypergraphs of boun...

Given a message msg ∈ {0, 1}N , its k-wise direct product encoding is the sequence of k-tuples (msg(i1), . . . ,msg(ik)) over all possible k-tuples of indices (i1, . . . , ik) ∈ {1, . . . , N}k. We give an efficient randomized algorithm for approximate local list-decoding of direct product codes. That is, given oracle access to a word which agrees with a k-wise direct product encoding of some m...