Results 1 to 10 of about 3,702,963 (209)

Singular quasilinear elliptic systems with gradient dependence [PDF]

Positivity, 2022
In this paper, we prove existence and regularity of positive solutions for singular quasilinear elliptic systems involving gradient terms. Our approach is based on comparison properties, a priori estimates and Schauder’s fixed point theorem.
Halima Dellouche, Abdelkrim Moussaoui
semanticscholar   +4 more sources

A Sub-Supersolution Approach for Robin Boundary Value Problems with Full Gradient Dependence

Mathematics, 2020
The paper investigates a nonlinear elliptic problem with a Robin boundary condition, which exhibits a convection term with full dependence on the solution and its gradient. A sub- supersolution approach is developed for this type of problems.
Dumitru Motreanu, Angela Sciammetta, Elisabetta Tornatore   +2 more
doaj   +2 more sources

Nodal solutions for Neumann systems with gradient dependence [PDF]

Boundary Value Problems
We consider the following convective Neumann systems: ( S ) { − Δ p 1 u 1 + | ∇ u 1 | p 1 u 1 + δ 1 = f 1 ( x , u 1 , u 2 , ∇ u 1 , ∇ u 2 ) in  Ω , − Δ p 2 u 2 + | ∇ u 2 | p 2 u 2 + δ 2 = f 2 ( x , u 1 , u 2 , ∇ u 1 , ∇ u 2 ) in  Ω , | ∇ u 1 | p 1 − 2 ...
Kamel Saoudi, Eadah Alzahrani, Dušan D. Repovš   +2 more
doaj   +2 more sources

Nonzero Positive Solutions of Elliptic Systems with Gradient Dependence and Functional BCs [PDF]

Advanced Nonlinear Studies, 2020
We discuss, by topological methods, the solvability of systems of second-order elliptic differential equations subject to functional boundary conditions under the presence of gradient terms in the nonlinearities.
Biagi Stefano, Calamai Alessandro, Infante Gennaro   +2 more
doaj   +2 more sources

Location of solutions for quasi-linear elliptic equations with general gradient dependence

Electronic Journal of Qualitative Theory of Differential Equations, 2017
Existence and location of solutions to a Dirichlet problem driven by $(p,q)$-Laplacian and containing a (convection) term fully depending on the solution and its gradient are established through the method of subsolution-supersolution.
Dumitru Motreanu, Elisabetta Tornatore
doaj   +2 more sources

Material dependence of Casimir forces: gradient expansion beyond proximity [PDF]

Applied Physics Letters, 2011
A widely used method for estimating Casimir interactions [H. B. G. Casimir, Proc. K. Ned. Akad. Wet. 51, 793 (1948)] between gently curved material surfaces at short distances is the proximity force approximation (PFA).
Casimir H. B. G., Giuseppe Bimonte, Lifshitz E. M., Mehran Kardar, Palik E. D., Rose M., Thorsten Emig   +6 more
core   +10 more sources

Hamilton-Jacobi-Bellman equations with fast gradient-dependence [PDF]

Indiana University Mathematics Journal, 2000
The authors deal with the existence, uniqueness, and regularity properties for a class of Hamilton-Jacobi-Bellman equations, when the Hamiltonians are superlinear in the adjoint variable, but possibly not uniformly with respect to the state variable. Such a class of equations arises in nonlinear control problems with unbounded controls.
F. Rampazzo, C. Sartori
semanticscholar   +4 more sources

Calcium gradient dependence of Neurospora crassa hyphal growth.

Microbiology, 2003
A tip-high cytoplasmic calcium gradient has been identified as a requirement for hyphal growth in the fungusNeurospora crassa. The Ca2+gradient is less steep compared to wall vesicle, wall incorporation and vesicular Ca2+gradients, but this can be explained by Ca2+diffusion.
L. Silverman-Gavrila, R. Lew
semanticscholar   +3 more sources

Weighted (p,q)-equations with gradient dependent reaction

Electronic Journal of Differential Equations
We consider a weighted (p,q)-equation with a parametric reaction  depending on the gradient. Using truncation and comparison techniques  and the theory of nonlinear operators of monotone type, we show  that for all small values of the parameter, the problem has a  positive smooth solution.
Zhao Jing, Zhenhai Liu, Nikolaos S. Papageorgiou   +2 more
doaj   +3 more sources

Multidimensional encoding of restricted and anisotropic diffusion by double rotation of the q vector [PDF]

Magnetic Resonance, 2023
Diffusion NMR and MRI methods building on the classic pulsed gradient spin-echo sequence are sensitive to many aspects of translational motion, including time and frequency dependence (“restriction”), anisotropy, and flow, leading to ambiguities when ...
H. Jiang, L. Svenningsson, D. Topgaard
doaj   +1 more source