Distinguished self-adjoint extension and eigenvalues of operators with gaps. Application to Dirac-Coulomb operators

Autor: Dolbeault, Jean, Esteban, Maria J., Séré, Eric
Rok vydání: 2022
Předmět:
Zdroj: J. Spectr. Theory 13 (2023), no. 2, pp. 491-524
Druh dokumentu: Working Paper
DOI: 10.4171/jst/461
Popis: We consider a linear symmetric operator in a Hilbert space that is neither bounded from above nor from below, admits a block decomposition corresponding to an orthogonal splitting of the Hilbert space and has a variational gap property associated with the block decomposition. A typical example is the Dirac-Coulomb operator defined on $C^\infty_c(\mathbb R^3\setminus\{0\}, \mathbb C^4)$. In this paper we define a distinguished self-adjoint extension with a spectral gap and characterize its eigenvalues in that gap by a min-max principle. This has been done in the past under technical conditions. Here we use a different, geometric strategy, to achieve that goal by making only minimal assumptions. Our result applied to the Dirac-Coulomb-like Hamitonians covers sign-changing potentials as well as molecules with an arbitrary number of nuclei having atomic numbers less than or equal to 137.
Databáze: arXiv