Polynomial approximation of divergence-free functions
نویسندگان
چکیده
منابع مشابه
Interpolation of nullspaces for polynomial approximation of divergence-free functions in a cube
The aim of this paper is the interpolation between nullspaces of a fixed partial differential operator in different Sobolev spaces, for example the subspaces of divergence-free functions. We present several methods of proofs, which allow for handling various operators in different geometries, with or without boundary conditions. Our application is the optimal approximation of divergence-free fu...
متن کاملPolynomial Approximation of Functions
Constructive proofs and several generalizations of approximation results of J. H. Bramble and S. R. Hubert are presented. Using an averaged Taylor series, we represent a function as a polynomial plus a remainder. The remainder can be manipulated in many ways to give different types of bounds. Approximation of functions in fractional order Sobolev spaces is treated as well as the usual integer o...
متن کاملThe best uniform polynomial approximation of two classes of rational functions
In this paper we obtain the explicit form of the best uniform polynomial approximations out of Pn of two classes of rational functions using properties of Chebyshev polynomials. In this way we present some new theorems and lemmas. Some examples will be given to support the results.
متن کاملPolynomial Approximation of Functions in Sobolev Spaces
Constructive proofs and several generalizations of approximation results of J. H. Bramble and S. R. Hubert are presented. Using an averaged Taylor series, we represent a function as a polynomial plus a remainder. The remainder can be manipulated in many ways to give different types of bounds. Approximation of functions in fractional order Sobolev spaces is treated as well as the usual integer o...
متن کاملA polynomial approximation for arbitrary functions
Abstract We describe an expansion of Legendre polynomials, analogous to the Taylor expansion, to approximate arbitrary functions. We show that the polynomial coefficients in Legendre expansion, thus, the whole series, converge to zero much more rapidly compared to the Taylor expansion of the same order. Furthermore, using numerical analysis with sixth-order polynomial expansion, we demonstrate ...
متن کاملذخیره 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: Mathematics of Computation
سال: 1989
ISSN: 0025-5718
DOI: 10.1090/s0025-5718-1989-0971405-9