Martin COSTABEL & Monique DAUGE Abstract. The 2 2 system of integral equations corresponding to the biharmonic single layer potential in R2 is known to be strongly elliptic. It is also known to be positive definite on a space of functions orthogonal to polynomials of degree one. We study the question of its unique solvability without this orthogonality condition. To each curve , we associate a ...

Time-frequency concentration operators restrict the integral analysis-synthesis formula for short-time Fourier transform to a given compact domain. We estimate how much corresponding eigenvalue counting function deviates from Lebesgue measure

We study the asymptotic distribution of eigenvalues of integral operators Tk defined by kernels k which belong to Triebel-Lizorkin function space Fσ pu(F qv) by using the factorization theorem and the Weyl numbers xn. We use the relation between Triebel-Lizorkin space Fσ pu(Ω) and Besov space Bτ pq(Ω) and the interpolation methods to get an estimation for the distribution of eigenvalues in Lizo...

The Karhunen-Loève expansion of a Gaussian process, a common tool on finite element methods for differential equations with stochastic coefficients, is based on the spectral decomposition of its covariance function. The eigenpairs of the covariance are expressed as a Fredholm integral equation of second kind, which can be readily approximated with piecewise-constant finite elements. In this wor...

Among the eigenvalue problems of the Laplacian, the biharmonic operator eigenvalue problems are interesting projects because these problems root in physics and geometric analysis. The buckling problem is one of the most important problems in physics, and many studies have been done by the researchers about the solution and the estimate of its eigenvalue. In this paper, first, we obtain the evol...

Recently, a kind of eigensolvers based on contour integral were developed for computing the eigenvalues inside a given region in the complex plane. The CIRR method is a classic example among this kind of methods. In this paper, we propose a contour-integral based QZ method which is also devoted to computing partial spectrum of generalized eigenvalue problems. Our new method takes advantage of t...

We present an alternative procedure for solving the eigenvalue problem of replicated transfer matrices describing disordered spin systems with (random) 1D nearest neighbour bonds and/or random fields, possibly in combination with (random) long range bonds. Our method is based on transforming the original eigenvalue problem for a 2 × 2 matrix (where n → 0) into an eigenvalue problem for integral...