Search results for "35S30"

showing 5 items of 5 documents

Positivity, complex FIOs, and Toeplitz operators

2018

International audience; We establish a characterization of complex linear canonical transformations that are positive with respect to a pair of strictly plurisubharmonic quadratic weights. As an application, we show that the boundedness of a class of Toeplitz operators on the Bargmann space is implied by the boundedness of their Weyl symbols.

Class (set theory)Pure mathematicsFourier integral operator in the complex domainPrimary: 32U05 32W25 35S30 47B35 70H1570H15Mathematics::Classical Analysis and ODEsOcean EngineeringCharacterization (mathematics)32U05 32W25 35S30 47B35 70H15Space (mathematics)01 natural sciencesMathematics - Analysis of PDEsQuadratic equation0103 physical sciencesFOS: Mathematics0101 mathematics[MATH]Mathematics [math]MathematicsMathematics::Functional Analysispositive canonical transformationMathematics::Complex Variables32U0532W25010102 general mathematicsToeplitz matrixFunctional Analysis (math.FA)Mathematics - Functional Analysis35S30Toeplitz operatorpositive Lagrangian plane010307 mathematical physicsstrictly plurisubharmonic quadratic form47B35Analysis of PDEs (math.AP)Toeplitz operator
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Characterizing boundedness of metaplectic Toeplitz operators

2023

We study Toeplitz operators on the Bargmann space, with Toeplitz symbols given by exponentials of complex quadratic forms. We show that the boundedness of the corresponding Weyl symbols is necessary for the boundedness of the operators, thereby completing the proof of the Berger-Coburn conjecture in this case. We also show that the compactness of such Toeplitz operators is equivalent to the vanishing of their Weyl symbols at infinity.

Mathematics - Functional Analysis32A36 32U05 32W25 35S30 47B35Mathematics - Complex VariablesFOS: MathematicsComplex Variables (math.CV)Functional Analysis (math.FA)
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Weyl symbols and boundedness of Toeplitz operators

2019

International audience; We study Toeplitz operators on the Bargmann space, with Toeplitz symbols that are exponentials of inhomogeneous quadratic polynomials. It is shown that the boundedness of such operators is implied by the boundedness of the corresponding Weyl symbols.

Mathematics::Functional AnalysisMathematics - Complex VariablesMathematics::Operator AlgebrasGeneral Mathematics010102 general mathematicsMathematics::Classical Analysis and ODEs32U05 32W25 35S30 47B3501 natural sciencesToeplitz matrixFunctional Analysis (math.FA)AlgebraMathematics - Functional AnalysisFOS: MathematicsComputer Science::Symbolic Computation0101 mathematicsComplex Variables (math.CV)[MATH]Mathematics [math]Mathematics
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Compactness of Fourier integral operators on weighted modulation spaces

2019

Using the matrix representation of Fourier integral operators with respect to a Gabor frame, we study their compactness on weighted modulation spaces. As a consequence, we recover and improve some compactness results for pseudodifferential operators.

Modulation spacePure mathematicsPseudodifferential operatorsApplied MathematicsGeneral Mathematics010102 general mathematicsMatrix representationGabor frame01 natural sciencesFourier integral operatorFunctional Analysis (math.FA)Mathematics - Functional Analysis35S30 47G30 42C15Compact spaceFOS: Mathematics0101 mathematicsMathematicsTransactions of the American Mathematical Society
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Spectral multipliers and wave equation for sub-Laplacians: lower regularity bounds of Euclidean type

2018

Let $\mathscr{L}$ be a smooth second-order real differential operator in divergence form on a manifold of dimension $n$. Under a bracket-generating condition, we show that the ranges of validity of spectral multiplier estimates of Mihlin--H\"ormander type and wave propagator estimates of Miyachi--Peral type for $\mathscr{L}$ cannot be wider than the corresponding ranges for the Laplace operator on $\mathbb{R}^n$. The result applies to all sub-Laplacians on Carnot groups and more general sub-Riemannian manifolds, without restrictions on the step. The proof hinges on a Fourier integral representation for the wave propagator associated with $\mathscr{L}$ and nondegeneracy properties of the sub…

osittaisdifferentiaaliyhtälötsub-LaplacianApplied MathematicsGeneral Mathematicsharmoninen analyysi35L05 35S30 42B15 43A22 58J60Functional Analysis (math.FA)Mathematics - Functional Analysiseikonal equationMathematics - Analysis of PDEsMathematics - Classical Analysis and ODEsClassical Analysis and ODEs (math.CA)FOS: Mathematicswave equationsub-Riemannian manifoldMathematics::Differential Geometryspectral multipliermonistotFourier integral operatorAnalysis of PDEs (math.AP)Journal of the European Mathematical Society
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