Spectral Methods with Sparse Matrices.
Spectral projection, residue of the scattering amplitude and Schrödinger group expansion for barrier-top resonances
We study the spectral projection associated to a barrier-top resonance for the semiclassical Schrödinger operator. First, we prove a resolvent estimate for complex energies close to such a resonance. Using that estimate and an explicit representation of the resonant states, we show that the spectral projection has a semiclassical expansion in integer powers of , and compute its leading term. We use this result to compute the residue of the scattering amplitude at such a resonance. Eventually, we...
Spectral projections for the twisted Laplacian
Let n ≥ 1, d = 2n, and let (x,y) ∈ ℝⁿ × ℝⁿ be a generic point in ℝ²ⁿ. The twisted Laplacian has the spectrum n + 2k = λ²: k a nonnegative integer. Let be the spectral projection onto the (infinite-dimensional) eigenspace. We find the optimal exponent ϱ(p) in the estimate for all p ∈ [2,∞], improving previous partial results by Ratnakumar, Rawat and Thangavelu, and by Stempak and Zienkiewicz. The expression for ϱ(p) is ϱ(p) = 1/p -1/2 if 2 ≤ p ≤ 2(d+1)/(d-1), ϱ(p) = (d-2)/2 - d/p if 2(d+1)/(d-1)...
Spectral properties of a solution to the Gellerstedt problem for mixed-type equations and their applications.
Spectral properties of compressible stratified flows.
Spectral properties of even order derivative operators.
Spectral properties of high contrast band-gap materials and operators on graphs.
Spectral properties of non-local uniformly-elliptic operators.
Spectral properties of Schrödinger operators and scattering theory
Spectral Properties of the Neumann Laplacian of Horns.
Spectral properties of vaguely elliptic pseudo differential operators with momentum dependent long range potentials using time dependent scattering theory - II.
Spectral Radius Properties for Layer Potentials Associated with the Elsastostatics and Hydrostatics Equations in Nonsmooth Domains.
Spectral Riesz-Cesàro means: How the square root function helps us to see around the world.
Spectral shift and multiplicity of the first eigenvalue of the magnetic Schrödinger operator in two dimensions
We show that the lowest eigenvalue of the magnetic Schrödinger operator on a line bundle over a compact Riemann surface is bounded by the -norm of the magnetic field . This implies a similar bound on the multiplicity of the ground state. An example shows that this degeneracy can indeed be comparable with even in case of the trivial bundle.
Spectral Shift Function for the Perturbations of Schrödinger Operators at High Energy
2000 Mathematics Subject Classification: 35P20, 35J10, 35Q40.We give a complete pointwise asymptotic expansion for the Spectral Shift Function for Schrödinger operators that are perturbations of the Laplacian on Rn with slowly decaying potentials.
Spectral statistics for random Schrödinger operators in the localized regime
We study various statistics related to the eigenvalues and eigenfunctions of random Hamiltonians in the localized regime. Consider a random Hamiltonian at an energy in the localized phase. Assume the density of states function is not too flat near . Restrict it to some large cube . Consider now , a small energy interval centered at that asymptotically contains infintely many eigenvalues when the volume of the cube grows to infinity. We prove that, with probability one in the large volume...
Spectral study of a self-adjoint operator on related with a Poincaré type constant
Spectral Tau Approximation of the Two-Dimensional Stokes Problem.
Spectral theory of corrugated surfaces
We discuss spectral and scattering theory of the discrete laplacian limited to a half-space. The interesting properties of such operators stem from the imposed boundary condition and are related to certain phenomena in surface physics.
Spectral theory of nonlinear operators