2024/01/05 by S. Krymskii, Krymskii, Stanislav · 1 citation
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Analysis of PDEs (math.AP) #FOS: Mathematics #Spectral Theory in Mathematical Physics #advanced mathematical theories
paper · pdf · doi:10.48550/arxiv.2401.02800
openalex publication_date 2024/01/05 · openalex created_date 2024/01/13 · openalex updated_date 2026/07/28
In this article we study the possible size of support of solutions to the discrete stationary Schrodinger equation Δu(x)+V(x)u(x)=0 in ℤd. We show that for any nonzero solution to any discrete stationary Schrodinger equation the dimension of the support is at least log2(d)-7. In the related setting of ℤ2-valued harmonic functions in ℤd one can improve the estimate on support's dimension to log2(d). However, we also provide an example where a ℤ2-valued harmonic function in ℤd has a fractal-like support with dimension log2(d)+1. This fractal satisfies a recurrence relation: X = 2X+\e1,-e1,…,ed,-ed\. This example and estimate provide an answer to the Malinnikova's question about the smallest size of set X⊂ℤd such that no cross contains exactly one point of X.