title: Compressed modes for variational problems in mathematics and physics.
abstract: This article describes a general formalism for obtaining spatially localized ("sparse") solutions to a class of problems in mathematical physics, which can be recast as variational optimization problems, such as the important case of Schrödinger's equation in quantum mechanics. Sparsity is achieved by adding an regularization term to the variational principle, which is shown to yield solutions with compact support ("compressed modes"). Linear combinations of these modes approximate the eigenvalue spectrum and eigenfunctions in a systematically improvable manner, and the localization properties of compressed modes make them an attractive choice for use with efficient numerical algorithms that scale linearly with the problem size.
authors.affiliation: Departments of Materials Science and Engineering, and Mathematics, University of California, Los Angeles, CA 90095-1555.
authors.forename: Vidvuds
authors.initials: V
authors.lastname: Ozolins
authors.forename: Rongjie
authors.initials: R
authors.lastname: Lai
authors.forename: Russel
authors.initials: R
authors.lastname: Caflisch
authors.forename: Stanley
authors.initials: S
authors.lastname: Osher
mesh_terms: D008433:Mathematics / Q000379:methods*; D008962:Models, Theoretical; D010825:Physics / Q000379:methods*; D011789:Quantum Theory