Results 11 to 20 of about 1,950,635 (268)
On Positivity Sets for Helmholtz Solutions
Vietnam Journal of Mathematics, 2023 AbstractWe address the question of finding global solutions of the Helmholtz equation that are positive in a given set. This question arises in inverse scattering for penetrable obstacles. In particular, we show that there are solutions that are positive on the boundary of a bounded Lipschitz domain.
Pu-Zhao Kow +2 more
openaire +5 more sources
Positive solutions of difference equations [PDF]
Proceedings of the American Mathematical Society, 1990 Necessary and sufficient condition for existence of positive solutions of the difference equation \((E)\quad (-1)^{m-1}\Delta^ mA_ n+\sum^{\infty}_{k=0}p_ kA_{n-\ell_ k}=0\) is established, where m is a positive integer, \((p_ k)_{k\geq 0}\) is a sequence of positive real numbers, \((\ell_ k)_{k\geq 0}\) is a sequence of integers with \(0\leq \ell_ ...
Philos, C. G., Sficas, Y. G.
openaire +3 more sources
Positive Solutions of Positive Linear Equations [PDF]
Proceedings of the American Mathematical Society, 1972 Let B B be a real vector lattice and a Banach space under a semimonotonic norm. Suppose
openaire +2 more sources
Algebraic Systems with Positive Coefficients and Positive Solutions
Mathematics, 2022 The paper is devoted to the existence, uniqueness and nonuniqueness of positive solutions to nonlinear algebraic systems of equations with positive coefficients. Such systems appear in large numbers of applications, such as steady-state equations in continuous and discrete dynamical models, Dirichlet problems, difference equations, boundary value ...
Ana Maria Acu +2 more
openaire +2 more sources
On Positive Solutions of the Heat Equation [PDF]
Nagoya Mathematical Journal, 1967 Consider the positive and twice continuously differentiable solutions u of the heat equationin an open t-strip Ω = Rn×(0,T) for some T>0, where Rn is the n-dimensional Euclidean space.In this note, we prove a theorem of Fatou type on u and, as its application, the uniqueness theorem for the Cauchy problem of ( 1 ).
openaire +2 more sources
A POSITIVE SOLUTION FOR A NONLOCAL SCHRÖDINGER EQUATION [PDF]
Bulletin of the Australian Mathematical Society, 2014 AbstractWe provide an existence result of radially symmetric, positive, classical solutions for a nonlinear Schrödinger equation driven by the infinitesimal generator of a rotationally invariant Lévy process.
Zhang, Yongchao, Zhu, Gaosheng
openaire +3 more sources
On the positive solutions of the Matukuma equation [PDF]
Duke Mathematical Journal, 1993 The author proves that for \(1< p0\). This completes the results obtained before by \textit{Y. Li} and \textit{W.-M. Ni} [Arch. Ration. Mech. Anal. 108, No. 2, 175-194 (1989; Zbl 0705.35039); ibid. 118, No. 3, 223-243 (1992; Zbl 0764.35014)].
openaire +5 more sources
Positive Solutions of a Class of Operator Equations [PDF]
Ukrainian Mathematical Journal, 2015 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Cvetkovic, Aleksandar +2 more
openaire +3 more sources
Positive solutions for nonvariational Robin problems
Asymptotic Analysis, 2018 We study a nonlinear Robin problem driven by the p-Laplacian and with a reaction term depending on the gradient (convection term). Using the theory of nonlinear operators of monotone-type and the asymptotic analysis of a suitable perturbation of the original equation, we show the existence of a positive smooth solution.
Nikolaos S. Papageorgiou +2 more
openaire +4 more sources
Right focal boundary value problems for difference equations [PDF]
Opuscula Mathematica, 2010 An application is made of a new Avery et al. fixed point theorem of compression and expansion functional type in the spirit of the original fixed point work of Leggett and Williams, to obtain positive solutions of the second order right focal discrete ...
Johnny Henderson +3 more
doaj +1 more source