منابع مشابه
Stability Modulus Singular Sets
A new concept of stability, closely related to that of structural stability, is introduced and applied to the study of Cr endomorphisms with singularities. A map that is stable in this sense will be conjugated to each perturbation that is equivalent to it in a geometric sense. It will be shown that this kind of stability implies Axiom A, Omega-stability and that every critical point is wanderin...
متن کاملMaximum likelihood separation of constant modulus signals
In this paper we derive a Newton scoring algorithm for the maximum likelihood separation and directionof-arrival estimation of constant modulus (CM) signals, using a sensors array. We present a rapidly converging scheme for the joint estimation of the signals and their directions, based on their CM property. We discuss initialization and show that the complexity is moderate. 2
متن کاملOn the Maximum Modulus of Polynomials. Ii
Let f(z) := ∑n ν=0 aνz ν be a polynomial of degree n having no zeros in the open unit disc, and suppose that max|z|=1 |f(z)| = 1. How small can max|z|=ρ |f(z)| be for any ρ ∈ [0 , 1)? This problem was considered and solved by Rivlin [4]. There are reasons to consider the same problem under the additional assumption that f ′(0) = 0. This was initiated by Govil [2] and followed up by the present ...
متن کاملOn the Structure of Maximum Modulus Algebras
i.e., if every fER attains its maximum modulus on C. As a matter of convenience, we shall, in this paper, abbreviate "maximum modulus algebra on K" to "ilf-algebra." Examples of Af-algebras which come to mind immediately are (a) the algebra ft consisting of all functions which are continuous on K and analytic in U, (b) any subalgebra of ft, (c) any algebra (B which is equivalent to an algebra o...
متن کاملThe maximum modulus of a trigonometric trinomial
Let Λ be a set of three integers and let CΛ be the space of 2π-periodic functions with spectrum in Λ endowed with the maximum modulus norm. We isolate the maximum modulus points x of trigonometric trinomials T ∈ CΛ and prove that x is unique unless |T | has an axis of symmetry. This permits to compute the exposed and the extreme points of the unit ball of CΛ, to describe how the maximum modulus...
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ژورنال
عنوان ژورنال: Annales de l’institut Fourier
سال: 1981
ISSN: 0373-0956
DOI: 10.5802/aif.837