2024/06/14 by Grigor'yan, Alexander, Lin, Yong, Yau, S. -T. +1
#Algebraic Topology (math.AT) #Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2406.09814
This paper aims to compute and estimate the eigenvalues of the Hodge Laplacians on directed graphs. We have devised a new method for computing Hodge spectra with the following two ingredients. (I) We have observed that the product rule does work for the so-called normalized Hodge operator, denoted by Δp(a), where a refers to the weight that is used to redefine the inner product in the spaces Ωp. This together with the Künneth formula for product allows us to compute inductively the spectra of all normalized Hodge operators Δp(a) on Cartesian powers including n-cubes and n-tori. (II) We relate in a certain way the spectra of Δp and Δp(a) to those of operators Lp=∂ ∗ ∂ also acting on Ωp. Knowing the spectra of Δp(a) for all values of p, we compute the spectra of Lp and then the spectra of Δp. This program yields the spectra of all operators Δp on all n-cubes and n-tori.