Results 251 to 260 of about 4,272 (299)

On Dugundji's Notion of Positive Definiteness [PDF]

Proceedings of the American Mathematical Society, 1974
Dugundji’s notion of positive definiteness is generalized to nonnegative real-valued functions on a uniform space. Its relations with completeness and various notions of compactness are investigated. For an arbitrary uniform space X
Chi Song Wong
openaire   +2 more sources

Verification of Positive Definiteness [PDF]

BIT Numerical Mathematics, 2006
An efficient numerical criterion to verify positive definiteness of a symmetric or Hermitian matrix is presented. The criterion is based on standard IEEE 754 floating-point arithmetic with rounding to nearest. It implements a single floating-point Cholesky decomposition and improves a known result.
Rump, Siegfried M.
openaire   +2 more sources

q-positive definiteness and related operators [PDF]

Journal of Mathematical Analysis and Applications, 2007
We are in progress of extending the family of ‘q-deformed operators’ considered in the previous papers by joining to them q-subnormal as well as q-formally subnormal ones.
Franciszek Hugon Szafraniec
exaly   +2 more sources

Conic positive definiteness and sharp minima of fractional orders in vector optimization problems [PDF]

Journal of Mathematical Analysis and Applications, 2012
Motivated by the fact that the usual positive definiteness does not work in an infinite space, we introduce the concept of S-positive definiteness with respect to an ordering cone in a general Banach space and show that the S-positive definiteness plays ...
Xi Yin Zheng
exaly   +2 more sources

Strict Positive Definiteness of a Product of Covariance Functions [PDF]

Communications in Statistics - Theory and Methods, 2011
Positive definiteness represents an admissibility condition for a function to be a covariance. Nevertheless, the more restricted condition of strict positive definiteness has received attention in literature, especially in spatial statistics, since it ...
Donato Posa, Donald Myers, Sandra De Iaco   +2 more
exaly   +2 more sources

Some of the next articles are maybe not open access.

Related searches:

On Different Definitions of Positive Definiteness

Mathematische Nachrichten, 1991
Let the function \(T^*\) be defined by \(T^*(a)=T(a^{-1})^*\) for a function \(T\) of a group \(G\) into a Hilbert space. The authors show that the commutativity of \(G\) is equivalent to each of the conditions below: (1) \(T^*\) is positive definite for every representation \(T\) of \(G\) in Hilbert space.
Friedrich, J., Klotz, L.
openaire   +1 more source

Positive Definiteness of a Class of Cyclic Symmetric Tensors [PDF]

Journal of Optimization Theory and Applications
For a 4th order 3-dimensional cyclic symmetric tensor, a sufficient and necessary condition is bulit for its positive semi-definiteness. A sufficient and necessary condition of positive definiteness is showed for a 4th order $n$-dimensional symmetric ...
Song Y S
exaly   +2 more sources

Extrapolated positive definite and positive semi-definite splitting methods for solving non-Hermitian positive definite linear systems

Applications of Mathematics, 2021
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Shokrpour, Raheleh, Ebadi, Ghodrat
openaire   +2 more sources

On the Measurability of Positive Definite and Conditionally Positive Definite Functions

Mathematische Nachrichten, 1986
Let f be a positive definite function on a locally compact abelian group G. In this paper we show that measurability of f on an open neighbourhood of the zero implies measurability of f on G. The same result holds for conditionally positive definite functions.
openaire   +1 more source