Buscar
Mostrando ítems 1-10 de 885
Extra Invariance of group actions
(Springer, 2021-07-28)
Given discrete groups Γ ⊂ Δ we characterize (Γ , σ) -invariant spaces that are also invariant under Δ. This will be done in terms of subspaces that we define using an appropriate Zak transform and a particular partition ...
Extra Invariance of a Shift-Invariant Space in LCA Groups
(Elsevier, 2010-10)
This article generalizes recent results in the extra invariance for shift-invariant spaces to the context of LCA groups. Let G be a locally compact abelian (LCA) group and K a closed subgroup of G. A closed subspace of ...
Invariance of a Shift-Invariant Space in Several Variables
(Springer, 2011-12)
In this article we study invariance properties of shift-invariant spaces in higher dimensions. We state and prove several necessary and sufficient conditions for a shift-invariant space to be invariant under a given closed ...
Form invariant transformations between n- and m-dimensional flat friedmann-robertson-walker cosmologies
(World Scientific, 2008-10)
We illustrate how a group of symmetry transformations, which preserve the form of the n-dimensional flat Friedmann-Robertson-Walker cosmologies satisfying Einstein's equations, act in any dimension. This group relates the ...
Closed expressions for Lie algebra invariants and finite transformations
(1997-12-01)
A simple procedure to obtain complete, closed expressions for Lie algebra invariants is presented. The invariants are ultimately polynomials in the group parameters. The construction of finite group elements requires the ...
Rotation-discriminating template matching based on Fourier coefficients of radial projections with robustness to scaling and partial occlusion
(ELSEVIER SCI LTD, 2010)
We consider brightness/contrast-invariant and rotation-discriminating template matching that searches an image to analyze A for a query image Q We propose to use the complex coefficients of the discrete Fourier transform ...