2009/03/31 by C. Bardos, Claude Bardos, I. Catto +5 · 1 citation
Mathematics · Physics and Astronomy · #Advanced Mathematical Physics Problems #Density matrix #Invertible matrix #Laser-Matter Interactions and Applications #Mathematical analysis #Mathematics #Matrix (chemical analysis) #Nonlinear system #Physics #Pure mathematics #Quantum mechanics #Schrödinger equation #Spectral Theory in Mathematical Physics #Uniqueness #Wave function #math-ph #math.AP #math.MP
paper · pdf · doi:10.1007/s00205-010-0308-8
48 pages, 1 figure
arxiv created 2009/04/27 · openalex publication_date 2010/04/19 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this paper we motivate, formulate and analyze the Multi-Configuration Time-Dependent Hartree-Fock (MCTDHF) equations for molecular systems under Coulomb interaction. They consist in approximating the N-particle Schrodinger wavefunction by a (time-dependent) linear combination of (time-dependent) Slater determinants. The equations of motion express as a system of ordinary differential equations for the expansion coefficients coupled to nonlinear Schrodinger-type equations for mono-electronic wavefunctions. The invertibility of the one-body density matrix (full-rank hypothesis) plays a crucial role in the analysis. Under the full-rank assumption a fiber bundle structure shows up and produces unitary equivalence between convenient representations of the equations. We discuss and establish existence and uniqueness of maximal solutions to the Cauchy problem in the energy space as long as the density matrix is not singular. A sufficient condition in terms of the energy of the initial data ensuring the global-in-time invertibility is provided (first result in this direction). Regularizing the density matrix breaks down energy conservation, however a global well-posedness for this system in L2 is obtained with Strichartz estimates. Eventually solutions to this regularized system are shown to converge to the original one on the time interval when the density matrix is invertible.