Results 51 to 60 of about 1,296 (214)
Operator Characterizations and Some Properties of g-Frames on Hilbert Spaces
Journal of Function Spaces and Applications, 2013 Given the g-orthonormal basis for Hilbert space H, we characterize the g-frames, normalized tight g-frames, and g-Riesz bases in terms of the g-preframe operators.
Xunxiang Guo
doaj +1 more source
ON THE INVERSE PROBLEM OF THE BITSADZE–SAMARSKII TYPE FOR A FRACTIONAL PARABOLIC EQUATION
Проблемы анализа, 2023 In this paper, the inverse problem of the Bitsadze–Samarsky type is studied for a fractional order equation with a Hadamard–Caputo fractional differentiation operator. The problem is solved using the spectral method.
R. R. Ashurov +2 more
doaj +1 more source
Hub‐and‐Spoke Collusion With a Third‐Party Pricing Algorithm
The Journal of Industrial Economics, Volume 74, Issue 2, Page 181-196, June 2026.ABSTRACT A data analytics company delivers an efficiency by supplying a pricing algorithm that allows prices to more effectively respond to demand variation. In this setting, I consider a new form of hub‐and‐spoke collusion: A data analytics company (hub) coordinates the prices of competitors (spokes) through its pricing algorithm.
Joseph E. Harrington Jr.
wiley +1 more source
Riesz basis property of Hill operators with potentials in weighted spaces [PDF]
Transactions of the Moscow Mathematical Society, 2014 Consider the Hill operator $L(v) = - d^2/dx^2 + v(x) $ on $[0,π]$ with Dirichlet, periodic or antiperiodic boundary conditions; then for large enough $n$ close to $n^2 $ there are one Dirichlet eigenvalue $μ_n$ and two periodic (if $n$ is even) or antiperiodic (if $n$ is odd) eigenvalues $λ_n^-, \, λ_n^+ $ (counted with multiplicity).
Djakov, Plamen, Mityagin, Boris
openaire +3 more sources
Riesz bases of port-Hamiltonian systems [PDF]
, 2020 The location of the spectrum and the Riesz basis property of well-posed homogeneous infinite-dimensional linear port-Hamiltonian systems on a 1D spatial domain are studied.
Zwart, Hans +3 more
core +1 more source
Perturbation of frames and Riesz bases in Hilbert C∗-modules
, 2009 We extend the Casazza–Christensen general perturbation theorem for Hilbert space frames to modular frames in Hilbert C∗-modules. In the Hilbert space setting, under the same perturbation condition, the perturbation of any Riesz basis remains to be a ...
Jing, Wu +2 more
core +2 more sources
Vestnik Samarskogo Gosudarstvennogo Tehničeskogo Universiteta. Seriâ: Fiziko-Matematičeskie Nauki, 2014 We made the comparison study and characterize the spectral properties of differential operators induced by the Dirichlet problem for the hyperbolic system without the lowest terms of the form $$ \cfrac{\partial^2{u^1}}{\partial{t}^2}+\cfrac{\partial^2{u ...
Olesya V Alexeeva +2 more
doaj +1 more source
Degree theory for 4‐dimensional asymptotically conical gradient expanding solitons
Communications on Pure and Applied Mathematics, Volume 79, Issue 5, Page 1151-1298, May 2026.Abstract We develop a new degree theory for 4‐dimensional, asymptotically conical gradient expanding solitons. Our theory implies the existence of gradient expanding solitons that are asymptotic to any given cone over S3$S^3$ with non‐negative scalar curvature. We also obtain a similar existence result for cones whose link is diffeomorphic to S3/Γ$S^3/\
Richard H. Bamler, Eric Chen
wiley +1 more source
Littlewood, Paley and almost‐orthogonality: a theory well ahead of its time
Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.Abstract The classic paper by Littlewood and Paley [J. Lond. Math. Soc. (1), 6 (1931), 230–233] marked the birth of Littlewood–Paley theory. We discuss this paper and its impact from a historical perspective, include an outline of the results in the paper and their subsequent significance in relation to developments over the last century, and set them ...
Anthony Carbery
wiley +1 more source
, 1996 We consider frames which contain a Riesz basis. Among those, we find Riesz frames, i.e., frames with the property that every subfamily is a frame for its closed linear span, with a common lower bound. We point out the connection to the projection method,
Christensen, Ole
core +1 more source