This is a survey of Harold Widom’s work in Toeplitz operators, embracing his early results on the invertibility and spectral theory investigations eigenvalue distribution convolution groundbreaking research into Wiener–Hopf determinants.

An approach to the optimal design of dynamic force/torque sensors is presented. The approach is based on the system invertibility properties of the truncated normal modes representation of an elastic beam. Theoretical results are connrmed by experiment simulations.

a INRIA, Domaine de Voluceau, B.P. 105, 78153 Le Chesnay Cedex, France. E-mail: [email protected] b INRIA, Domaine de Voluceau, B.P. 105, 78153 Le Chesnay Cedex, France. E-mail: [email protected] c Dep. of Computing and Mathematics, Nottingham Trent University, Burton Street, Nottingham, NG1 4BU, UK, and Institute for Information Transmission Problems of Russian Academy of Science...

We begin this lecture by asking why should an arbitrary n × n Gaussian matrix A be invertible? That is, does there exist a lower bound on the smallest singular value s n (A) = inf x∈S n−1 Ax 2 ≥ c √ n where c > 0 is an absolute constant. There are two reasons (or cases) which we will pursue in this lecture. 1. In Lecture 15 we saw that the invertibility of rectangular (i.e., non-square) Gaussia...

Abstract The classes of band-dominated operators and the subclass in Wiener algebra $${\mathcal {W}}$$ W are known to be inverse closed. This paper studies extends partially results that type for one-sided generalized invertibility. Furthermore, invertibility, Fredholm property index independent underlying sp...

An explicit counterexample shows that contrary to the situation in the special Colombeau algebra, positivity and invertibility cannot be characterized pointwise in algebras of tempered generalized functions. Further a point value characterization of the latter is refined.

In this paper we give a representation of the Moore-Penrose inverse of a linear combination of generalized and hypergeneralized projectors. Also, we consider the invertibility of some linear combination of commuting generalized and hypergeneralized projectors.

This paper derives an algorithm which determines the invertibility of arbitrary two-dimensional quadratic isoparametric finite element transformations. Theorems verifying the algorithm and guiding the construction of invertible transformations are proven.

This paper considers estimation of moving average (MA) models with non-Gaussian errors. Information in higher order cumulants allows identification of the parameters without imposing invertibility. By allowing for an unbounded parameter space, the generalized method of moments estimator of the MA(1) model has classical (root-T and asymptotic normal) properties when the moving average root is in...

Motion artifacts are a significant issue in medical image reconstruction. There are many methods for incorporating motion information into image reconstruction. However, there are fewer studies that focus on deformation regularization in motioncompensated image reconstruction. The usual choice for deformation regularization has been penalty functions based on the assumption that tissues are ela...