Searcharxiv⌕ Search

arXiv · math-ph/0511016

Inverse scattering problem for a special class of canonical systems and non-linear Fourier integral. Part I: asymptotics of eigenfunctions

Abstract

An original approach to the inverse scattering for Jacobi matrices was suggested in a recent paper by Volberg-Yuditskii. The authors considered quite sophisticated spectral sets (including Cantor sets of positive Lebesgue measure), however they did not take into account the mass point spectrum. This paper follows similar lines for the continuous setting with an absolutely continuous spectrum on the half-axis and a pure point spectrum on the negative half-axis satisfying the Blaschke condition. This leads us to the solution of the inverse scattering problem for a class of canonical systems that generalizes the case of Sturm-Liouville (Schrödinger) operator.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. Kupin, F. Peherstorfer, A. Volberg, P. Yuditskii. 2005-11-04. Inverse scattering problem for a special class of canonical systems and non-linear Fourier integral. Part I: asymptotics of eigenfunctions. https://arxiv.org/abs/math-ph/0511016

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Magnetism and infrared divergence in a Hubbard-phonon interacting system

We study a finite Hubbard model coupled to a massless phonon field through a form factor common to all sites that satisfies the infrared singular condition. The Hamiltonian has no ground state in the Fock representation. With the unitary transformation of Arai and Hirokawa, the ground states with infrared cutoff define states on the Weyl algebra over the form domain of the inverse dispersion, and they converge to a ground state in a representation inequivalent to the Fock representation. In this representation the ground states are the products of the ground states of the Hubbard model and the phonon vacuum, so that the model has ferromagnetic or unique spin-singlet ground states according to the hopping matrix and the electron number.

math-ph↗

Phonon Bose-Einstein condensation in a Hubbard-phonon interacting system with infrared divergence

We study the grand canonical Gibbs states of a finite Hubbard model coupled to massless phonons with the dispersion relation $|k|^s$, $1\leq s<d$, at finite temperature. We keep the decoupling setting of the zero-temperature analysis, in which the electron-phonon form factor is common to all sites. An explicit unitary transformation factorizes the Gibbs state into the electron Gibbs state and the free phonon Gibbs state up to a phase, and the phonons exhibit Bose-Einstein condensation in the thermodynamic limit with the critical density of the free Bose gas. Assuming the convergence of this phase as the infrared cutoff is removed, the condensed state is the mixture of mutually disjoint component states with broken gauge symmetry, described by their expectations on the Weyl algebra. Physically, phonons are considered not to undergo Bose-Einstein condensation arxiv:1207.4621, and the study of a mechanism that suppresses this mathematical and formal condensation is left for future research.

math-ph↗

Equilibrium-energy-scaled quantum lattice Boltzmann method for variable-velocity linear advection--diffusion equations

We develop a quantum lattice Boltzmann method for linear advection--diffusion equations with prescribed space- and time-dependent velocities. Direct block-encoding can accumulate normalization factors that suppress success probability exponentially, even when the classical propagator remains bounded. We control this loss by scaling each distribution component by the inverse square root of its local equilibrium weight. For uniformly positive weights and dimensionless relaxation times $τ^*\geq 1/2$, this equilibrium energy scaling gives the Bhatnagar--Gross--Krook collision operator unit spectral norm while preserving the discrete dynamics. Streaming normalization depends on weight ratios at the departure and arrival positions and times of each step; these ratios equal one for uniform steady advection. For periodic streaming, cumulative normalization stays bounded under mesh refinement at fixed physical time if logarithmic derivatives of the weights along streaming trajectories are bounded uniformly in space, time, and mesh resolution. A single-step block-encoding with two flag qubits supports coherent propagation of the full kinetic distribution without intermediate measurements. We compare oracle query bounds for time marching with those for a history-state linear system built from the same scaled operator, under specified assumptions on initial-state preparation and coefficient access. Tests in one and two dimensions and noiseless circuit simulations verify the construction. In a controlled comparison after 50 steps, scaling increases the probability of preparing the quantum state encoding the terminal distribution by approximately $450\times$. Classical refinement diagnostics up to $N_t=16{,}384$ steps confirm bounded cumulative normalization. The scaling controls additional normalization losses while retaining physical diffusive attenuation.

math-ph↗