Unicity and strong unicity in approximation theory

نویسندگان

چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effective bounds on strong unicity in L1-approximation

In this paper we present another case study in the general project of Proof Mining which means the logical analysis of prima facie non-effective proofs with the aim of extracting new computationally relevant data. We use techniques based on monotone functional interpretation (developed in [18]) to analyze Cheney’s simplification [6] of Jackson’s original proof [10] from 1921 of the uniqueness o...

متن کامل

Unicity Subspaces in L ’ - Approximation

In 1918 A. Haar [4] characterized those n-dimensional subspaces U, of C[O, l] for which there exists a unique best approximation to every realvalued function f E C[O, l] in the uniform (L”) norm. Haar proved that uniqueness always holds if and only if U, is a Tchebycheff (T-) system on [0, 11, or what is sometimes referred to as a Haar system (or Haar space). This simply means that no u E U,\ {...

متن کامل

Strong unicity criterion in some space of operators

Let X be a finite dimensional Banach space and let Y ⊂ X be a hyperplane. Let L Y = {L ∈ L (X, Y ) : L |Y = 0}. In this note, we present sufficient and necessary conditions on L0 ∈ L Y being a strongly unique best approximation for given L ∈ L (X). Next we apply this characterization to the case of X = l ∞ and to generalization of Theorem I.1.3 from [12] (see also [13]).

متن کامل

Unicity in piecewise polynomial L1-approximation via an algorithm

Our main result shows that certain generalized convex functions on a real interval possess a unique best L1 approximation from the family of piecewise polynomial functions of fixed degree with varying knots. This result was anticipated by Kioustelidis in [11]; however the proof given there is nonconstructive and uses topological degree as the primary tool, in a fashion similar to the proof the ...

متن کامل

On the problem of Unicity in Einstein-Sciama-Kibble Theory

We consider the ESK theory, based on the principle for which the space is filled with matter fields in such a way that Cartan torsion is spin; in the geometry in which Cartan torsion tensor is completely antisymmetric then spin has to be completely antisymmetric as well: we will show how spin complete antisymmetry constraints the form of possible matter field theories as to allow the special ca...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Approximation Theory

سال: 1979

ISSN: 0021-9045

DOI: 10.1016/0021-9045(79)90132-1