In this paper, we study the multiplicity of positive solutions for the Laplacian systems with sign-changing weight functions. Using the decomposition of the Nehari manifold, we prove that an elliptic system has at least two positive solutions.

In this paper, we define new subclass of analytic functions related with bounded positive real part, and coefficients estimates, duality and neighborhood are considered.

It is well known that if all the elementary symmetric functions of the eigenvalues of an n–by–n matrix are positive, then all its eigenvalues lie in the region of the complex plane {z : −π + πn < argz < π − π n}. Let A denote an n–by–n matrix with all diagonal entries nonzero and for which the length of the longest cycle in its directed graph is k, 2 ≤ k ≤ n. If, in addition, all the cycles in ...

systems, each of which violates the like-numbered postulate and satisfies all the other postulates of the set. These examples are all arithmetic systems, the elements being the numbers 0 and 1. The symbol/(a , b) (mod 2) in an arithmetic system denotes the least positive residue modulo 2 obtained from /(a , b) by rejecting multiples of 2. The operations + and X are to be interpreted as the oper...

In this paper, the class of harmonic functions f = h+ ḡ with positive real part and normalized by f(ζ) = 1, (|ζ| < 1) is studied, where h and g are analytic in U = {z : |z| < 1}. Some properties of this class are searched. Sharp coefficient relations are given for functions in this class. On the other hand, the author make use of Alexander integral transforms of certain analytic functions (whic...

Concepts of abstract harmonic analysis can be used to provide a unifying framework for basis function methods, like radial basis functions in Euclidean spaces or zonal basis functions on the sphere. To illustrate how these concepts can be applied reflection invariant functions are considered. A specialization of the BochnerGodement Theorem leads to a characterization of suitable basis functions. §