Results 11 to 20 of about 327,801 (268)
Optimal version of the Picard–Lindelöf theorem
Electronic Journal of Qualitative Theory of Differential Equations, 2021 Consider the differential equation $y'=F(x,y)$. We determine the weakest possible upper bound on $|F(x,y)-F(x,z)|$ which guarantees that this equation has for all initial values a unique solution, which exists globally.
Jan-Christoph Schlage-Puchta
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On a viscoelastic heat equation with logarithmic nonlinearity
Electronic Journal of Qualitative Theory of Differential Equations, 2022 This work deals with the following viscoelastic heat equations with logarithmic nonlinearity \begin{align*} u_t-\Delta u+\int_{0}^{t}g(t-s)\Delta u(s)ds=\vert u\vert^{p-2}u\ln\vert u\vert.
Nguyen Van Y, Nhan Le, Le Xuan Truong
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ON THE GLOBAL EXISTENCE OF TIME [PDF]
International Journal of Modern Physics D, 2009 The global existence of time is often taken for granted but should instead be considered for investigation. Using the tools of global Lorentzian geometry the author shows that, under physically reasonable conditions, the impossibility of finding a global time implies the singularity of space–time.
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Global existence and boundedness for quasi-variational systems
International Journal of Mathematics and Mathematical Sciences, 1999 We consider quasi-variational ordinary differential systems, which may be considered as the motion law for holonomic mechanical systems. Even when the potential energy of the system is not bounded from below, by constructing appropriate Liapunov ...
Giancarlo Cantarelli
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Global regularity of the 3D generalized MHD equations with only velocity dissipation
上海师范大学学报. 自然科学版, 2019 In this paper, we consider the global regularity of the three-dimensinal (3D) generalized magnetohydrodynamic (MHD) equations with only velocity dissipation in terms of fractional Laplacians. By the Galerkin approximation methods, the compactness and the
CAI Xiaojing, LIU Bingyu
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On the existence of global bisections of Lie groupoids [PDF]
Acta Mathematica Sinica, English Series, 2009 We show that every source connected Lie groupoid always has global bisections through any given point. This bisection can be chosen to be the multiplication of some exponentials as close as possible to a prescribed curve. The existence of bisections through more than one prescribed points is also discussed.
Zhong, Deshou, Chen, Zhuo, Liu, Zhangju
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Blow-up analysis for a doubly nonlinear parabolic system with multi-coupled nonlinearities
Electronic Journal of Qualitative Theory of Differential Equations, 2012 This paper deals with the global existence and the global nonexistence of a doubly nonlinear parabolic system coupled via both nonlinear reaction terms and nonlinear boundary flux.
Jian Wang, Yanyan Ge
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Uniform boundedness and extinction results of solutions to a predator–prey system
Electronic Journal of Qualitative Theory of Differential Equations, 2020 Global existence, positivity, uniform boundedness and extinction results of solutions to a system of reaction-diffusion equations on unbounded domain modeling two species on a predator–prey relationship is considered.
Mokhtar Kirane +2 more
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Existence and stability results of a nonlinear Timoshenko equation with damping and source terms [PDF]
Theoretical and Applied Mechanics, 2021 In this paper, we consider a nonlinear Timoshenko equation. First, we prove the local existence solution by the Faedo–Galerkin method, and, under suitable assumptions with positive initial energy, we prove that the local existence is global in time ...
Ouaoua Amar, Khaldi Aya, Maouni Messaoud
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On the Existence of Global Variational Principles
American Journal of Mathematics, 1980 In studying physical phenomena one frequently encounters differential equations which arise from a variational principle, i.e. the equations are the Euler-Lagrangequations obtained from the fundamental (or action) integral of a problem in the calculus of variations. Because solutions to the Euler-Lagrange equations determine the possible extrema of the
Anderson, Ian M., Duchamp, T.
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