TL;DR: In this article, the authors present a self-contained account of the spectral theory of non-self-adjoint linear operators, including pseudospectra and trace class operators.
Abstract: This wide ranging but self-contained account of the spectral theory of non-self-adjoint linear operators is ideal for postgraduate students and researchers, and contains many illustrative examples and exercises. Fredholm theory, Hilbert-Schmidt and trace class operators are discussed, as are one-parameter semigroups and perturbations of their generators. Two chapters are devoted to using these tools to analyze Markov semigroups. The text also provides a thorough account of the new theory of pseudospectra, and presents the recent analysis by the author and Barry Simon of the form of the pseudospectra at the boundary of the numerical range. This was a key ingredient in the determination of properties of the zeros of certain orthogonal polynomials on the unit circle. Finally, two methods, both very recent, for obtaining bounds on the eigenvalues of non-self-adjoint Schrodinger operators are described. The text concludes with a description of the surprising spectral properties of the non-self-adjoint harmonic oscillator.
TL;DR: In this article, it was shown that the Lieb-thirring inequalities on moments of negative eigenvalues of Schrodinger-like operators remain true, with possibly different constants, when the critical Hardy-weight C │x│^(-2) is subtracted from the Laplace operator.
Abstract: We show that the Lieb-Thirring inequalities on moments of negative eigenvalues of Schrodinger-like operators remain true, with possibly different constants, when the critical Hardy-weight C │x│^(-2) is subtracted from the Laplace operator. We do so by first establishing a Sobolev inequality for such operators. Similar results are true for fractional powers of the Laplacian and the Hardy-weight and, in particular, for relativistic Schrodinger operators. We also allow for the inclusion of magnetic vector potentials. As an application, we extend, for the first time, the proof of stability of relativistic matter with magnetic fields all the way up to the critical value of the nuclear charge Zɑ = 2/π, for ɑ less than some critical value.
TL;DR: The Hardy-Littlewood maximal operator in weighted Lorentz spaces has been studied in this article, where the authors define boundedness of operators on characteristic functions and the Hardy operator.
Abstract: Introduction Boundedness of operators on characteristic functions and the Hardy operator Lorentz spaces The Hardy-Littlewood maximal operator in weighted Lorentz spaces Bibliography Index.
TL;DR: In this paper, a good-? inequality with two parameters and Calderon?Zygmund decomposition are used to obtain weighted norm estimates for singular non-integral operators with bounded mean oscillation functions.
TL;DR: The Laplace-Poisson equation as discussed by the authors, Distributions, Sobolev spaces on R n and R n+ domains, and Spectral theory in Hilbert spaces and Banach spaces, Compact embeddings, spectral theory of elliptic operators, and integral formulae.
Abstract: The Laplace-Poisson equation -- Distributions -- Sobolev spaces on R-n and R-n+ -- Sobolev spaces on domains -- Elliptic operators in L-2 -- Spectral theory in Hilbert spaces and Banach spaces -- Compact embeddings, spectral theory of elliptic operators -- Domains, basic spaces, and integral formulae -- Orthonormal bases of trigonometric functions -- Operator theory -- Some integral inequalities -- Function spaces.
TL;DR: In this paper, an explicit construction of a family of W(2,2p−1) modules, which decompose as direct sum of simple Virasoro algebra modules, was obtained for every p⩾2.
Abstract: For every p⩾2, we obtained an explicit construction of a family of W(2,2p−1) modules, which decompose as direct sum of simple Virasoro algebra modules. Furthermore, we classified all irreducible self-dual W(2,2p−1) modules, we described their internal structure, and computed their graded dimensions. In addition, we constructed certain hidden logarithmic intertwining operators among two ordinary and one logarithmic W(2,2p−1) modules. This work, in particular, gives a mathematically precise formulation and interpretation of what physicists have been referring to as “logarithmic conformal field theory” of central charge cp,1=1−[6(p−1)2∕p], p⩾2. Our explicit construction can be easily applied for computations of correlation functions. Techniques from this paper can be used to study the triplet vertex operator algebra W(2,(2p−1)3) and other logarithmic models.
TL;DR: Estimates for classical interpolation operators for finite elements, like the Scott–Zhang operator, in the context of Orlicz–Sobolev spaces are shown with respect to quasi-norms which appear in the study of systems of p-Laplace type.
Abstract: We study classical interpolation operators for finite elements, like the Scott–Zhang operator, in the context of Orlicz–Sobolev spaces. Furthermore, we show estimates for these operators with respect to quasi-norms which appear in the study of systems of p-Laplace type.
TL;DR: For a symmetric operator or relation A with infinite deficiency indices in a Hilbert space, this paper developed an abstract framework for the description of symmetric and selfadjoint extensions A of A of a relation T as restrictions of an operator T which is a core of the adjoint A.
Abstract: For a symmetric operator or relation A with infinite deficiency indices in a Hilbert space we develop an abstract framework for the description of symmetric and selfadjoint extensions A of A as restrictions of an operator or relation T which is a core of the adjoint A . This concept is applied to second order elliptic partial dierential operators on smooth bounded domains, and a class of elliptic problems with eigenvalue dependent boundary conditions is investigated.
TL;DR: A covering model for granular computing in a set-theoretic setting is studied and it is proved that the duality is always true for the two pairs of lower and upper approximation operators.
TL;DR: The theory of random Schrodinger operators is devoted to the mathematical analysis of quantum mechanical Hamiltonians modeling disordered solids as mentioned in this paper, and it is a multifaceted subject in its own right, drawing on ideas and methods from various mathematical disciplines like functional analysis, selfadjoint operators, PDE, stochastic processes and multiscale methods.
Abstract: The theory of random Schrodinger operators is devoted to the mathematical analysis of quantum mechanical Hamiltonians modeling disordered solids Apart from its importance in physics, it is a multifaceted subject in its own right, drawing on ideas and methods from various mathematical disciplines like functional analysis, selfadjoint operators, PDE, stochastic processes and multiscale methods
The present text describes in detail a quantity encoding spectral features of random operators: the integrated density of states or spectral distribution function Various approaches to the construction of the integrated density of states and the proof of its regularity properties are presented
The setting is general enough to apply to random operators on Riemannian manifolds with a discrete group action References to and a discussion of other properties of the IDS are included, as are a variety of models beyond those treated in detail here
TL;DR: For a linear relation in a linear space the concepts of ascent, descent, nullity, and defect are introduced and studied in this article, and it is shown that the results of A.E. Taylor and M.A. Kaashoek concerning the relationship between ascent and descent for linear operators remain valid in the context of linear relations, sometimes under the additional condition that the linear relation does not have any nontrivial singular chains.
TL;DR: In this paper, the authors investigated the integral operators Tg and Ig on the unit disk, where Tg is an extension of the Cesaro operator and Ig is the radial derivative of h. The boundedness and compactness of these integral operators were investigated.
Abstract: Let H(B) denote the space of all holomorphic functions on the unit ball In this article, we investigate the following integral operators f∈ H(B), z∈ B, where g∈ H(B) and is the radial derivative of h. The operator Tg can be considered as an extension of the Cesaro operator on the unit disk. The boundedness and compactness of the operators Tg and Ig , as well as of the product of the operators between the weighted Bloch spaces are considered.
TL;DR: The Fitzpatrick function of the sum of two operators is investigated, and it is shown that a known upper bound is actually exact in finite-dimensional and more general settings.
Abstract: The notion of a maximal monotone operator is crucial in optimization as it captures both the subdifferential operator of a convex, lower semicontinuous, and proper function and any (not necessarily symmetric) continuous linear positive operator. It was recently discovered that most fundamental results on maximal monotone operators allow simpler proofs utilizing Fitzpatrick functions. In this paper, we study Fitzpatrick functions of continuous linear monotone operators defined on a Hilbert space. A novel characterization of skew operators is presented. A result by Brezis and Haraux is reproved using the Fitzpatrick function. We investigate the Fitzpatrick function of the sum of two operators, and we show that a known upper bound is actually exact in finite-dimensional and more general settings. Cyclic monotonicity properties are also analyzed, and closed forms of the Fitzpatrick functions of all orders are provided for all rotators in the Euclidean plane.
TL;DR: In this paper, a unified point of view on time-frequency representations and pseudo-differential operators is presented. And the TT-transform is applied to magnetic resonance imaging texture analysis by T. Ashino, T. Mandai, A. Morimoto, and F. Wong.
Abstract: On Hormander operators and non-holonomic geometry by P. Greiner Weyl transforms and the inverse of the sub-Laplacian on the Heisenberg group by A. Dasgupta and M. W. Wong Pseudo-differential calculus on manifolds with geometric singularities by B.-W. Schulze Corner operators and applications to elliptic complexes by C.-I. Martin Ellipticity of a class of corner operators by N. Dines Pseudodifferential methods for boundary value problems by C. L. Epstein Invertibility of parabolic Pseudodifferential operators by V. Rabinovich Semilinear pseudo-differential equations and travelling waves by M. Cappiello, T. Gramchev, and L. Rodino Continuity and compactness properties of pseudo-differential operators by E. Buzano and J. Toft Trace ideals for Fourier integral operators with non-smooth symbols by F. Concetti and J. Toft Schatten-von Neumann norm inequalities for two-wavelet localization operators by V. Catana Why use the S-transform? by R. G. Stockwell Applying the S-transform to magnetic resonance imaging texture analysis by T. A. Bjarnason, S. Drabycz, D. H. Adler, J. G. Cairncross, and J. R. Mitchell Inversion formulas for two-dimensional Stockwell transforms by Y. Liu and M. W. Wong Localization of signal and image features with the TT-transform by C. R. Pinnegar Weight functions in time-frequency analysis by K. Grochenig Shannon type sampling theorems on the Heisenberg group by R. R. Radha and S. Sivananthan Rihaczek transforms and pseudo-differential operators by A. Mohammed and M. W. Wong A unified point of view on time-frequency representations and pseudo-differential operators by P. Boggiatto, G. De Donno, and A. Oliaro Blind source separation using time-frequency analysis by R. Ashino, T. Mandai, A. Morimoto, and F. Sasaki.
TL;DR: Cerutti and Ferrari as discussed by the authors showed that Lipschitz free boundaries are smooth in the case of quasilinear operators of the form div ( A ( x, u ) ∇ u ) with Lipschnitz coefficients.
TL;DR: In this article, an operator based nonlinear control system of an aluminum plate with a Peltier device is designed by using operator theory, and the performance of the designed system is confirmed by simulation.
Abstract: In this paper, operator based nonlinear control system of an aluminum plate with a Peltier device is designed by using operator theory. A model of an aluminum plate with a Peltier device is derived. The parameters on Peltier device of model is evaluated by experiment. After that, operator based nonlinear temperature control system by using robust right coprime factorization is designed for the model. The effectiveness of the designed system is confirmed by simulation.
TL;DR: In this paper, the boundedness and compactness of integral operators T g and L g from mixed-norm spaces to the α-Bloch space ℬα and the little α-bloch space on the unit ball are discussed.
Abstract: Let g: B→ℂ1 be a holomorphic map of the unit ball B. We study the following integral operators The boundedness and compactness of operators T g and L g from mixed-norm spaces to the α-Bloch space ℬα and the little α-Bloch space on the unit ball are discussed in this article.
TL;DR: In this paper, the inverse problem of spectral analysis for a quadratic pencil of Sturm-Liouville operators on a finite interval is considered, and a uniqueness theorem is proved, a solution algorithm is presented, and sufficient conditions for the solubility of the problem are obtained.
Abstract: The inverse problem of spectral analysis for a quadratic pencil of Sturm-Liouville operators on a finite interval is considered. A uniqueness theorem is proved, a solution algorithm is presented, and sufficient conditions for the solubility of the inverse problem are obtained. Bibliography: 31 titles.
TL;DR: In this paper, it was shown that the Neumann, Dirichlet and regularity problems for divergence form elliptic equations in the half space are well posed for small complex perturbations of a coefficient matrix which is either real symmetric, of block form or constant.
Abstract: We prove that the Neumann, Dirichlet and regularity problems for divergence form elliptic equations in the half space are well posed in $L_2$ for small complex $L_\infty$ perturbations of a coefficient matrix which is either real symmetric, of block form or constant. All matrices are assumed to be independent of the transversal coordinate. We solve the Neumann, Dirichlet and regularity problems through a new boundary operator method which makes use of operators in the functional calculus of an underlaying first order Dirac type operator. We establish quadratic estimates for this Dirac operator, which implies that the associated Hardy projection operators are bounded and depend continuously on the coefficient matrix. We also prove that certain transmission problems for $k$-forms are well posed for small perturbations of block matrices.
TL;DR: In this article, the inverse spectral problem on a finite interval for the integro-differential operator l which is the perturbation of the Sturm-Liouville operator by the Volterra integral operator is studied.
Abstract: In this paper, we study the inverse spectral problem on a finite interval for the integro-differential operator l which is the perturbation of the Sturm-Liouville operator by the Volterra integral operator. The potential q belongs to L2[0, π] and the kernel of the integral perturbation is integrable in its domain of definition. We obtain a local solution of the inverse reconstruction problem for the potential q, given the kernel of the integral perturbation, and prove the stability of this solution. For the spectral data we take the spectra of two operators given by the expression for l and by two pairs of boundary conditions coinciding at one of the finite points.
TL;DR: In this paper, the authors examined logarithmic intertwining operators associated with rank one Heisenberg vertex operator algebra M(1)a, of central charge 1 − 12a2.
Abstract: This is the first in a series of papers where we study logarithmic intertwining operators for various vertex subalgebras of Heisenberg and lattice vertex algebras. In this paper we examine logarithmic intertwining operators associated with rank one Heisenberg vertex operator algebra M(1)a, of central charge 1 − 12a2. We classify these operators in terms of depth and provide explicit constructions in all cases. Our intertwining operators resemble puncture operators appearing in quantum Liouville field theory. Furthermore, for a = 0 we focus on the vertex operator subalgebra L(1, 0) of M(1)0 and obtain logarithmic intertwining operators among indecomposable Virasoro algebra modules. In particular, we construct explicitly a family of hidden logarithmic intertwining operators, i.e., those that operate among two ordinary and one genuine logarithmic L(1, 0)-module.
TL;DR: In this paper, it was shown that a non-trivial H-multiplier sequence is a Q-complex zero decreasing sequence (Q-CZDS) if and only if γk ≥ 0.
Abstract: If {γk}k=0 is a sequence of real numbers and Q = {qk(x)} ∞ k=0 is a sequence of polynomials satisfying deg(qk) = k for all non-negative integers k, then we can define a linear operator TQ on the vector space of real polynomials by TQ[qk(x)] = γkqk(x) (k = 0, 1, 2, . . . ). If the linear operator TQ has the property that it maps every real polynomial having only real zeros into another polynomial having only real zeros (or, perhaps, to the identically zero function), then the corresponding sequence {γk}k=0 is called a Qmultiplier sequence. Similarly, if the linear operator TQ has the property that it does not increase the number of non-real zeros of any polynomial (which it does not map to the identically zero function), then the corresponding sequence {γk}k=0 is called a Q-complex zero decreasing sequence, or, for brevity, a Q-CZDS. Pólya and Schur completely characterized all multiplier sequences for the standard basis { x }∞ k=0 , which we will call the classical multiplier sequences. Turán, and subsequently Bleecker and Csordas, discovered classes of H-multiplier sequences, where H denotes the set of Hermite polynomials. In this dissertation, we completely characterize H-multiplier sequences and, therefore, solve an open problem stated in the literature six years ago. We show that a sequence {γk}k=0 is a non-trivial Hmultiplier sequence if and only if {γk}k=0 is a classical multiplier sequence and, either 0 ≤ γk ≤ γk+1, or 0 ≥ γk ≥ γk+1 for all integers k ≥ 0. In order to establish this result, we prove a significant generalization of a curve theorem due to Pólya.
TL;DR: In this paper, the existence of common universal vectors for various uncountable families of universal sequence of linear operators is proved. But this criterion relies on some tools from Probability Theory and depends on the geometry of the underlying Banach space.
Abstract: We prove the existence of common universal vectors for various uncountable families of universal sequence of linear operators. In particular, we give a criterion for a one-parameter family of operators on a Banach space to have a common hypercyclic vector. This criterion relies on some tools from Probability Theory and depends on the geometry of the underlying Banach space. We also study several specific examples, such as shift operators or translation-dilation operators.
TL;DR: In this paper, the authors show that the space of Lax operators is closed with respect to their usual multiplication as matrix-valued functions, and construct orthogonal and symplectic analogs of the Lax operator and prove that they form almost graded Lie algebras.
Abstract: In this paper, we develop the general approach, introduced in [l], to Lax operators on algebraic curves. We observe that the space of Lax operators is closed with respect to their usual multiplication as matrix-valued functions. We construct orthogonal and symplectic analogs of Lax operators, prove that they form almost graded Lie algebras, and construct local central extensions of these Lie algebras.
TL;DR: In this article, a new aspect of the L p-extension problem for Inhomogeneous Differential Equations (Lp-extensions) is introduced for In-homogeneous Diffraction Equations.
Abstract: The Quantization of Edge Symbols- On Rays of Minimal Growth for Elliptic Cone Operators- Symbolic Calculus of Pseudo-differential Operators and Curvature of Manifolds- Weyl Transforms, Heat Kernels, Green Functions and Riemann Zeta Functions on Compact Lie Groups- On the Fourier Analysis of Operators on the Torus- Wave Kernels of the Twisted Laplacian- Super-exponential Decay of Solutions to Differential Equations in ?d- Gevrey Local Solvability for Degenerate Parabolic Operators of Higher Order- A New Aspect of the L p-extension Problem for Inhomogeneous Differential Equations- Continuity in Quasi-homogeneous Sobolev Spaces for Pseudo-differential Operators with Besov Symbols- Continuity and Schatten Properties for Pseudo-differential Operators on Modulation Spaces- Algebras of Pseudo-differential Operators with Discontinuous Symbols- A Class of Quadratic Time-frequency Representations Based on the Short-time Fourier Transform- A Characterization of Stockwell Spectra- Exact and Numerical Inversion of Pseudo-differential Operators and Applications to Signal Processing- On the Product of Localization Operators- Gelfand-Shilov Spaces, Pseudo-differential Operators and Localization Operators- Continuity and Schatten Properties for Toeplitz Operators on Modulation Spaces- Microlocalization within Some Classes of Fourier Hyperfunctions
TL;DR: In this paper, an operation "twisting" on Hochschild complex by analogy with Drinfeld's twisting operations was introduced, and the twisting and derived bracket construction was used to study differential graded Lie algebra structures associated with bi-graded Hochdescale complex.
Abstract: We will introduce an operation "twisting" on Hochschild complex by analogy with Drinfeld's twisting operations. By using the twisting and derived bracket construction, we will study differential graded Lie algebra structures associated with bi-graded Hochschild complex. We will show that Rota-Baxter type operators are solutions of Maurer-Cartan equations. As an application of twisting, we will give a construction of associative Nijenhuis operators.
TL;DR: In this article, the nonlocal boundary value problems for anisotropic partial differential-operator equations with a dependent coefficients are studied and several conditions for the maximal regularity and the fredholmness in Banach-valued L p -spaces are given.