Minimization of the First Nonzero Eigenvalue Problem for Two-Phase Conductors with Neumann Boundary Conditions

2020 ◽  
Vol 80 (4) ◽  
pp. 1607-1628 ◽  
Author(s):  
Di Kang ◽  
Patrick Choi ◽  
Chiu-Yen Kao
2013 ◽  
Vol 33 (1) ◽  
pp. 9
Author(s):  
Ahmed Dakkak ◽  
Siham El Habib ◽  
Najib Tsouli

This work deals with an indefinite weight one dimensional eigenvalue problem of the p-Laplacian operator subject to Neumann boundary conditions. We are interested in some properties of the spectrum like simplicity, monotonicity and strict monotonicity with respect to the weight. We also aim the study of zeros points of eigenfunctions.


2009 ◽  
Vol 2009 ◽  
pp. 1-27 ◽  
Author(s):  
Wei Li ◽  
Ping Yan

Consider the half-eigenvalue problem(ϕp(x′))′+λa(t)ϕp(x+)−λb(t)ϕp(x−)=0a.e.t∈[0,1], where1<p<∞,ϕp(x)=|x|p−2x,x±(⋅)=max⁡{±x(⋅),0}forx∈&#x1D49E;0:=C([0,1],ℝ), anda(t)andb(t)are indefinite integrable weights in the Lebesgue spaceℒγ:=Lγ([0,1],ℝ),1≤γ≤∞. We characterize the spectra structure under periodic, antiperiodic, Dirichlet, and Neumann boundary conditions, respectively. Furthermore, all these half-eigenvalues are continuous in(a,b)∈(ℒγ,wγ)2, wherewγdenotes the weak topology inℒγspace. The Dirichlet and the Neumann half-eigenvalues are continuously Fréchet differentiable in(a,b)∈(ℒγ,‖⋅‖γ)2, where‖⋅‖γis theLγnorm ofℒγ.


2009 ◽  
Vol 51 (3) ◽  
pp. 619-630
Author(s):  
JULIÁN FERNÁNDEZ BONDER ◽  
RAFAEL ORIVE ◽  
JULIO D. ROSSI

AbstractIn this paper we study homogenisation problems for Sobolev trace embedding H1(Ω) ↪ Lq(∂Ω) in a bounded smooth domain. When q = 2 this leads to a Steklov-like eigenvalue problem. We deal with the best constant of the Sobolev trace embedding in rapidly oscillating periodic media, and we consider H1 and Lq spaces with weights that are periodic in space. We find that extremals for these embeddings converge to a solution of a homogenised limit problem, and the best trace constant converges to a homogenised best trace constant. Our results are in fact more general; we can also consider general operators of the form aɛ(x, ∇u) with non-linear Neumann boundary conditions. In particular, we can deal with the embedding W1,p(Ω) ↪ Lq(∂Ω).


1990 ◽  
Vol 116 (1-2) ◽  
pp. 133-160 ◽  
Author(s):  
Jack Carr ◽  
Robert Pego

SynopsisWe consider the above equation on the interval 0 ≦ x ≦ 1 subject to Neumann boundary conditions with f(u) = F′(u) where F is a double well energy density function with equal minima. Our previous work [3] proved the existence and persistence of very slowly evolving patterns (metastable states) in solutions with two-phase initial data. Here we characterise these metastable states in terms of the global unstable manifolds of equilibria, as conjectured by Fusco and Hale [6].


1991 ◽  
Vol 117 (3-4) ◽  
pp. 225-250 ◽  
Author(s):  
C. Budd ◽  
M. C. Knaap ◽  
L. A. Peletier

SynopsisAsymptotic estimates are established for nontrivial positive radial eigenfunctions of the nonlinear eigenvalue problem −Δu= λ(up−uq) in the unit ballBin ℝN(N> 2) with Neumann boundary conditions, as the supremum norm tends to infinity. Herepis the critical Sobolev exponent (N+ 2)/(N− 2) and 0 <q<p− 1 = 4/(N− 2).


2020 ◽  
Vol 18 (1) ◽  
pp. 1552-1564
Author(s):  
Huimin Tian ◽  
Lingling Zhang

Abstract In this paper, the blow-up analyses in nonlocal reaction diffusion equations with time-dependent coefficients are investigated under Neumann boundary conditions. By constructing some suitable auxiliary functions and using differential inequality techniques, we show some sufficient conditions to ensure that the solution u ( x , t ) u(x,t) blows up at a finite time under appropriate measure sense. Furthermore, an upper and a lower bound on blow-up time are derived under some appropriate assumptions. At last, two examples are presented to illustrate the application of our main results.


2020 ◽  
Vol 28 (2) ◽  
pp. 237-241
Author(s):  
Biljana M. Vojvodic ◽  
Vladimir M. Vladicic

AbstractThis paper deals with non-self-adjoint differential operators with two constant delays generated by {-y^{\prime\prime}+q_{1}(x)y(x-\tau_{1})+(-1)^{i}q_{2}(x)y(x-\tau_{2})}, where {\frac{\pi}{3}\leq\tau_{2}<\frac{\pi}{2}<2\tau_{2}\leq\tau_{1}<\pi} and potentials {q_{j}} are real-valued functions, {q_{j}\in L^{2}[0,\pi]}. We will prove that the delays and the potentials are uniquely determined from the spectra of four boundary value problems: two of them under boundary conditions {y(0)=y(\pi)=0} and the remaining two under boundary conditions {y(0)=y^{\prime}(\pi)=0}.


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