2017/10/10 by Huyuan Chen, Chen, Huyuan, Tobias Weth +1 · 7 citations
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Analysis of PDEs (math.AP) #FOS: Mathematics #Nonlinear Partial Differential Equations #Numerical methods in inverse problems
paper · pdf · doi:10.48550/arxiv.1710.03416
openalex publication_date 2017/10/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we study the logarithmic Laplacian operator LΔ, which is a singular integral operator with symbol 2log |ζ|. We show that this operator has the integral representation LΔu(x) = cN ∫ℝN \frac u(x)1B1(x)(y)-u(y)|x-y|N dy + ρN u(x) with cN = π- (N)/(2) Γ((N)/(2)) and ρN=2 log 2 + ψ((N)/(2)) -γ, where Γ is the Gamma function, ψ= \fracΓ'Γ is the Digamma function and γ= -Γ'(1) is the Euler Mascheroni constant. This operator arises as formal derivative ∂s |s=0 (-Δ)s of fractional Laplacians at s= 0. We develop the functional analytic framework for Dirichlet problems involving the logarithmic Laplacian on bounded domains and use it to characterize the asymptotics of principal Dirichlet eigenvalues and eigenfunctions of (-Δ)s as s → 0. As a byproduct, we then derive a Faber-Krahn type inequality for the principal Dirichlet eigenvalue of LΔ. Using this inequality, we also establish conditions on domains giving rise to the maximum principle in weak and strong forms. This allows us to also derive regularity up to the boundary of solutions to corresponding Poisson problems.