Fitness noise in the Bak-Sneppen evolution model in high dimensions

We study the Bak-Sneppen evolution model on a regular hypercubic lattice in high dimensions. Recent work Phys. Rev. E 108, 044109 (2023) 2470-004510. 1103/PhysRevE. 108. 044109 showed the emergence of the 1/f^α noise for the fitness observable with α≈1. 2 in one-dimension (1D) and α≈2 for the random neighbor (mean-field) version of the model. We examine the temporal correlation of fitness in 2, 3, 4, and 5 dimensions. As obtained by finite-size scaling, the spectral exponent tends to take the mean-field value at the upper critical dimension Dₔ=4, which is consistent with previous studies. Our approach provides an alternative way to understand the upper critical dimension of the model. We also show the local activity power spectra, which offer insight into the return time statistics and the avalanche dimension.