Principal Eigenvalue

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 7941 Experts worldwide ranked by ideXlab platform

Naoyuki Ichihara - One of the best experts on this subject based on the ideXlab platform.

Yuan Lou - One of the best experts on this subject based on the ideXlab platform.

  • the generalised Principal Eigenvalue of time periodic nonlocal dispersal operators and applications
    Journal of Differential Equations, 2020
    Co-Authors: Yuan Lou, Feiying Yang
    Abstract:

    Abstract This paper is mainly concerned with the generalised Principal Eigenvalue for time-periodic nonlocal dispersal operators. We first establish the equivalence between two different characterisations of the generalised Principal Eigenvalue. We further investigate the dependence of the generalised Principal Eigenvalue on the frequency of the periodic oscillation, the dispersal rate and the dispersal spread. Finally, these qualitative results for time-periodic linear operators are applied to time-periodic nonlinear KPP equations with nonlocal dispersal, focusing on the effects of the frequency of the periodic oscillation, the dispersal rate and the dispersal spread on the existence and stability of positive time-periodic solutions to nonlinear equations.

  • the generalised Principal Eigenvalue of time periodic nonlocal dispersal operators and applications
    arXiv: Analysis of PDEs, 2019
    Co-Authors: Yuan Lou, Feiying Yang
    Abstract:

    This paper is mainly concerned with the generalised Principal Eigenvalue for time-periodic nonlocal dispersal operators. We first establish the equivalence between two different characterisations of the generalised Principal Eigenvalue. We further investigate the dependence of the generalised Principal Eigenvalue on the frequency, the dispersal rate and the dispersal spread. Finally, these qualitative results for time-periodic linear operators are applied to time-periodic nonlinear KPP equations with nonlocal dispersal, focusing on the effects of the frequency, the dispersal rate and the dispersal spread on the existence and stability of positive time-periodic solutions to nonlinear equations.

  • monotonicity of the Principal Eigenvalue for a linear time periodic parabolic operator
    arXiv: Analysis of PDEs, 2019
    Co-Authors: Shuang Liu, Yuan Lou, Rui Peng, Maolin Zhou
    Abstract:

    We investigate the effect of frequency on the Principal Eigenvalue of a time-periodic parabolic operator with Dirichlet, Robin or Neumann boundary conditions. The monotonicity and asymptotic behaviors of the Principal Eigenvalue with respect to the frequency parameter are established. Our results prove a conjecture raised by Hutson, Michaikow and Polacik [2001 J. Math. Biol.].

  • asymptotic behavior of the Principal Eigenvalue for cooperative elliptic systems and applications
    Journal of Dynamics and Differential Equations, 2016
    Co-Authors: Kingyeung Lam, Yuan Lou
    Abstract:

    The asymptotic behavior of the Principal Eigenvalue for general linear cooperative elliptic systems with small diffusion rates is determined. As an application, we show that if a cooperative system of ordinary differential equations has a unique positive equilibrium which is globally asymptotically stable, then the corresponding reaction-diffusion system with either the Neumann boundary condition or the Robin boundary condition also has a unique positive steady state which is globally asymptotically stable, provided that the diffusion coefficients are sufficiently small. Moreover, as the diffusion coefficients approach zero, the positive steady state of the reaction-diffusion system converges uniformly to the equilibrium of the corresponding kinetic system.

  • Principal Eigenvalue for an elliptic problem with indefinite weight on cylindrical domains
    Mathematical Biosciences and Engineering, 2008
    Co-Authors: Chiuyen Kao, Yuan Lou, Eiji Yanagida
    Abstract:

    This paper is concerned with an indefinite weight linear Eigenvalue problem in cylindrical domains. We investigate the minimization of the positive Principal Eigenvalue under the constraint that the weight is bounded by a positive and a negative constant and the total weight is a fixed negative constant. Biologically, this minimization problem is motivated by the question of determining the optimal spatial arrangement of favorable and unfavorable regions for a species to survive. Both our analysis and numerical simulations for rectangular domains indicate that there exists a threshold value such that if the total weight is below this threshold value, then the optimal favorable region is a circular-type domain at one of the four corners, and a strip at the one end with shorter edge otherwise.

Henri Berestycki - One of the best experts on this subject based on the ideXlab platform.

  • on the definition and the properties of the Principal Eigenvalue of some nonlocal operators
    Journal of Functional Analysis, 2016
    Co-Authors: Henri Berestycki, Jerome Coville
    Abstract:

    In this article we study some spectral properties of the linear operator $\mathcal{L}_{\Omega}+a$ defined on the space $C(\bar\Omega)$ by : $$ \mathcal{L}_{\Omega}[\varphi] +a\varphi:=\int_{\Omega}K(x,y)\varphi(y)\,dy+a(x)\varphi(x)$$ where $\Omega\subset \mathbb{R}^N$ is a domain, possibly unbounded, $a$ is a continuous bounded function and $K$ is a continuous, non negative kernel satisfying an integrability condition. We focus our analysis on the properties of the generalised Principal Eigenvalue $\lambda_p(\mathcal{L}_{\Omega}+a)$ defined by $$\lambda_p(\mathcal{L}_{\Omega}+a):= \sup\{\lambda \in \mathbb{R} \,|\, \exists \varphi \in C(\bar \Omega), \varphi>0, \textit{ such that }\; \mathcal{L}_{\Omega}[\varphi] +a\varphi +\lambda\varphi \le 0 \; \text{ in }\;\Omega\}. $$ We establish some new properties of this generalised Principal Eigenvalue $\lambda_p$. Namely, we prove the equivalence of different definitions of the Principal Eigenvalue. We also study the behaviour of $\lambda_p(\mathcal{L}_{\Omega}+a)$ with respect to some scaling of $K$. For kernels $K$ of the type, $K(x,y)=J(x-y)$ with $J$ a compactly supported probability density, we also establish some asymptotic properties of $\lambda_{p} \left(\mathcal{L}_{\sigma,m,\Omega} -\frac{1}{\sigma^m}+a\right)$ where $\mathcal{L}_{\sigma,m,\Omega}$ is defined by $\displaystyle{\mathcal{L}_{\sigma,m,\Omega}[\varphi]:=\frac{1}{\sigma^{2+N}}\int_{\Omega}J\left(\frac{x-y}{\sigma}\right)\varphi(y)\, dy}$. In particular, we prove that $$\lim_{\sigma\to 0}\lambda_p\left(\mathcal{L}_{\sigma,2,\Omega}-\frac{1}{\sigma^{2}}+a\right)=\lambda_1\left(\frac{D_2(J)}{2N}\Delta +a\right),$$ where $D_2(J):=\int_{\mathbb{R}^N}J(z)|z|^2\,dz$ and $\lambda_1$ denotes the Dirichlet Principal Eigenvalue of the elliptic operator. In addition, we obtain some convergence results for the corresponding eigenfunction $\varphi_{p,\sigma}$.

  • On the definition and the properties of the Principal Eigenvalue of some nonlocal operators
    Journal of Functional Analysis, 2016
    Co-Authors: Henri Berestycki, Jerome Coville
    Abstract:

    In this article we study some spectral properties of the linear operator L-Omega + a defined on the space C((Omega) over bar) by: L-Omega[phi] + a phi := integral(Omega) K(x, y)phi(y) dy + a(x)phi(x) where Omega C R-N is a domain, possibly unbounded, a is a continuous bounded function and K is a continuous, non-negative kernel satisfying an integrability condition. We focus our analysis on the properties of the generalised Principal Eigenvalue lambda(p)(L-Omega + a) defined by lambda(p)(L-Omega + a) := sup{lambda is an element of R vertical bar there exists phi is an element of C((Omega) over bar), phi > 0, such that L-Omega[phi] + a phi + lambda phi 0) lambda(p) (L-sigma,L-m,L-Omega - 1/sigma(2) + a) = lambda(1) (D-2(J)/2N Delta+a), where D-2(J) := integral(RN) J(z)vertical bar z vertical bar(2) dz and lambda(1) enotes the Dirichlet Principal Eigenvalue of the elliptic operator. In addition, we obtain some convergence results for the corresponding eigenfunction phi(p,sigma).

  • on the definition and the properties of the Principal Eigenvalue of some nonlocal operators
    arXiv: Analysis of PDEs, 2015
    Co-Authors: Henri Berestycki, Jerome Coville
    Abstract:

    In this article we study some spectral properties of the linear operator $\mathcal{L}\_{\Omega}+a$ defined on the space $C(\bar\Omega)$ by :$$ \mathcal{L}\_{\Omega}[\varphi] +a\varphi:=\int\_{\Omega}K(x,y)\varphi(y)\,dy+a(x)\varphi(x)$$ where $\Omega\subset \mathbb{R}^N$ is a domain, possibly unbounded, $a$ is a continuous bounded function and $K$ is a continuous, non negative kernel satisfying an integrability condition. We focus our analysis on the properties of the generalised Principal Eigenvalue $\lambda\_p(\mathcal{L}\_{\Omega}+a)$ defined by $$\lambda\_p(\mathcal{L}\_{\Omega}+a):= \sup\{\lambda \in \mathbb{R} \,|\, \exists \varphi \in C(\bar \Omega), \varphi\textgreater{}0, \textit{such that}\, \mathcal{L}\_{\Omega}[\varphi] +a\varphi +\lambda\varphi \le 0 \, \text{in}\;\Omega\}. $$ We establish some new properties of this generalised Principal Eigenvalue $\lambda\_p$. Namely, we prove the equivalence of different definitions of the Principal Eigenvalue. We also study the behaviour of $\lambda\_p(\mathcal{L}\_{\Omega}+a)$ with respect to some scaling of $K$. For kernels $K$ of the type, $K(x,y)=J(x-y)$ with $J$ a compactly supported probability density, we also establish some asymptotic properties of $\lambda\_{p} \left(\mathcal{L}\_{\sigma,m,\Omega} -\frac{1}{\sigma^m}+a\right)$ where $\mathcal{L}\_{\sigma,m,\Omega}$ is defined by $\displaystyle{\mathcal{L}\_{\sigma,m,\Omega}[\varphi]:=\frac{1}{\sigma^{2+N}}\int\_{\Omega}J\left(\frac{x-y}{\sigma}\right)\varphi(y)\, dy}$. In particular, we prove that $$\lim\_{\sigma\to 0}\lambda\_p\left(\mathcal{L}\_{\sigma,2,\Omega}-\frac{1}{\sigma^{2}}+a\right)=\lambda\_1\left(\frac{D\_2(J)}{2N}\Delta +a\right),$$where $D\_2(J):=\int\_{\mathbb{R}^N}J(z)|z|^2\,dz$ and $\lambda\_1$ denotes the Dirichlet Principal Eigenvalue of the elliptic operator. In addition, we obtain some convergence results for the corresponding eigenfunction $\varphi\_{p,\sigma}$.

  • generalizations and properties of the Principal Eigenvalue of elliptic operators in unbounded domains
    Communications on Pure and Applied Mathematics, 2015
    Co-Authors: Henri Berestycki, Luca Rossi
    Abstract:

    Using three different notions of the generalized Principal Eigenvalue of linear second-order elliptic operators in unbounded domains, we derive necessary and sufficient conditions for the validity of the maximum principle, as well as for the existence of positive eigenfunctions for the Dirichlet problem. Relations between these Principal Eigenvalues, their simplicity, and several other properties are further discussed. © 2015 Wiley Periodicals, Inc.

  • Maximum Principle and generalized Principal Eigenvalue for degenerate elliptic operators
    Journal de Mathématiques Pures et Appliquées, 2015
    Co-Authors: Henri Berestycki, Italo Capuzzo Dolcetta, Alessio Porretta, Luca Rossi
    Abstract:

    We characterize the validity of the Maximum Principle in bounded domains for fully nonlinear degenerate elliptic operators in terms of the sign of a suitably defined generalized Principal Eigenvalue. Here, the maximum principle refers to the property of non-positivity of viscosity subsolutions of the Dirichlet problem. The new notion of generalized Principal Eigenvalue that we introduce here allows us to deal with arbitrary type of degeneracy of the elliptic operators. We further discuss the relations between this notion and other natural generalizations of the classical notion of Principal Eigenvalue, some of which have been previously introduced for particular classes of operators.

Emmanuel Chasseigne - One of the best experts on this subject based on the ideXlab platform.

Luca Rossi - One of the best experts on this subject based on the ideXlab platform.