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Pólya's conjecture up to $ε$-loss and quantitative estimates for the remainder of Weyl's law

Renjin Jiang, Fanghua Lin

Abstract

Let $Ω\subset\mathbb{R}^n$ be a bounded Lipschitz domain. For any $ε\in (0,1)$ we show that for any Dirichlet eigenvalue $λ_k(Ω)>Λ(ε,Ω)$, it holds \begin{align*} k&\le (1+ε)\frac{|Ω|ω(n)}{(2π)^n}λ_k(Ω)^{n/2}, \end{align*} where $Λ(ε,Ω)$ is given explicitly. This reduces the $ε$-loss version of Pólya's conjecture to a computational problem. This estimate is based on quantitative estimates on the remainder of the Weyl law with explicit constants, which we give a new proof without using Neumann eigenvalues. Our arguments in deriving such uniform estimates yield also, in all dimensions $n\ge 2$, classes of domains that may even have rather irregular shapes or boundaries but satisfy Pólya's conjecture. Another key observation is that on strip-tiling domains (and therefore any triangles for instance) one actually has better eigenvalue estimates than Pólya conjectured.

Pólya's conjecture up to $ε$-loss and quantitative estimates for the remainder of Weyl's law

Abstract

Let be a bounded Lipschitz domain. For any we show that for any Dirichlet eigenvalue , it holds \begin{align*} k&\le (1+ε)\frac{|Ω|ω(n)}{(2π)^n}λ_k(Ω)^{n/2}, \end{align*} where is given explicitly. This reduces the -loss version of Pólya's conjecture to a computational problem. This estimate is based on quantitative estimates on the remainder of the Weyl law with explicit constants, which we give a new proof without using Neumann eigenvalues. Our arguments in deriving such uniform estimates yield also, in all dimensions , classes of domains that may even have rather irregular shapes or boundaries but satisfy Pólya's conjecture. Another key observation is that on strip-tiling domains (and therefore any triangles for instance) one actually has better eigenvalue estimates than Pólya conjectured.

Paper Structure

This paper contains 13 sections, 21 theorems, 205 equations, 5 figures.

Key Result

Theorem 1.3

Let $\Omega\subset{\mathbb R}^n$ be a bounded Lipschitz domain, $n\ge 2$. For any $0<\epsilon<1$, it holds for all $\lambda_k(\Omega)\ge \Lambda(\epsilon,\Omega)$ that where $\Lambda(\epsilon,\Omega)\ge \mathrm{width}(\Omega)^{-2}$ is such that Moreover, if $\Omega$ is convex, then $\Lambda(\epsilon,\Omega)$ can be taken smaller as

Figures (5)

  • Figure 1: Examples of strip-tiling domains in two dimension
  • Figure 2: Examples satisfying Pólya's conjecture
  • Figure 3: The 1/2 sum is controlled by the 1/4 ball
  • Figure 4: Examples of strip-tiling domains in two dimension
  • Figure 5: Whitney decomposition for the complementary of a convex set

Theorems & Definitions (48)

  • Definition 1.2
  • Theorem 1.3
  • Definition 1.4: Minimal Admissible rectangle
  • Theorem 1.5
  • Corollary 1.6
  • Definition 1.7: Strip-tiling domains
  • Remark 1.8
  • Theorem 1.9
  • Theorem 1.10
  • Corollary 1.11
  • ...and 38 more