Integral and nonnegativity preserving approximations of functions

Integral and Nonnegativity Preserving Approximations of Functions

In this paper we consider the problem of approximating a function by continuous piecewise linear functions that preserve the integral and nonnegativity of the original function.

Functions Preserving Nonnegativity of Matrices

The main goal of this work is to determine which entire functions preserve nonnegativity of matrices of a fixed order n— i.e., to characterize entire functions f with the property that f(A) is entrywise nonnegative for every entrywise nonnegative matrix A of size n×n. Towards this goal, we present a complete characterization of functions preserving nonnegativity of (block) uppertriangular matri...

Triangular approximations of fuzzy number with value and ambiguity functions

Linear Functions Preserving Multivariate and Directional Majorization

Let V and W be two real vector spaces and let &sim be a relation on both V and W. A linear function T : V → W is said to be a linear preserver (respectively strong linear preserver) of &sim if Tx &sim Ty whenever x &sim y (respectively Tx &sim Ty if and only if x &sim y). In this paper we characterize all linear functions T : M_{n,m} → M_{n,k} which preserve or strongly preserve multivariate an...

Integral Properties of Zonal Spherical Functions, Hypergeometric Functions and Invariant

Some integral properties of zonal spherical functions, hypergeometric functions and invariant polynomials are studied for real normed division algebras.