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An analogue of Gutzmer's formula for Hermite expansions

S. Thangavelu (2008)

Studia Mathematica

We prove an analogue of Gutzmer's formula for Hermite expansions. As a consequence we obtain a new proof of a characterisation of the image of L²(ℝⁿ) under the Hermite semigroup. We also obtain some new orthogonality relations for complexified Hermite functions.

An uncertainty principle related to the Poisson summation formula

K. Gröchenig (1996)

Studia Mathematica

We prove a class of uncertainty principles of the form S g f 1 C ( x a f p + ω b f ̂ q ) , where S g f is the short time Fourier transform of f. We obtain a characterization of the range of parameters a,b,p,q for which such an uncertainty principle holds. Counter-examples are constructed using Gabor expansions and unimodular polynomials. These uncertainty principles relate the decay of f and f̂ to their behaviour in phase space. Two applications are given: (a) If such an inequality holds, then the Poisson summation formula is valid...

Anisotropic viscoelastic body subjected to the pulsating load

Jozef Sumec, Mária Minárová, Ľuboš Hruštinec (2023)

Applications of Mathematics

Constitutive equations of continuum mechanics of the solid phase of anisotropic material is focused in the paper. First, a synoptic one-dimensional Maxwell model is explored, subjected to arbitrary deformation load. The explicit form is derived for stress on strain dependence. Further, the analogous explicit constitutive equation is taken in three spatial dimensions and treated mathematically. Later on, a simply supported straight concrete beam reinforced by the steel fibres is taken as an investigated...

Asymptotic Fourier and Laplace transformations for hyperfunctions

Michael Langenbruch (2011)

Studia Mathematica

We develop an elementary theory of Fourier and Laplace transformations for exponentially decreasing hyperfunctions. Since any hyperfunction can be extended to an exponentially decreasing hyperfunction, this provides simple notions of asymptotic Fourier and Laplace transformations for hyperfunctions, improving the existing models. This is used to prove criteria for the uniqueness and solvability of the abstract Cauchy problem in Fréchet spaces.

Average decay of Fourier transforms and geometry of convex sets.

Luca Brandolini, Marco Rigoli, Giancarlo Travaglini (1998)

Revista Matemática Iberoamericana

Let B be a convex body in R2, with piecewise smooth boundary and let ^χB denote the Fourier transform of its characteristic function. In this paper we determine the admissible decays of the spherical Lp averages of ^χB and we relate our analysis to a problem in the geometry of convex sets. As an application we obtain sharp results on the average number of integer lattice points in large bodies randomly positioned in the plane.

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