2019/11/06 by Bauer, Wolfram, Furutani, Kenro, Iwasaki, Chisato +1
#58J50 #58J53 #Differential Geometry (math.DG) #FOS: Mathematics #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.1911.02378
We determine the spectrum of the sub-Laplacian on pseudo H-type nilmanifolds and present pairs of isospectral but non-diffeomorphic nilmanifolds with respect to the sub-Laplacian. We observe that these pairs are also isospectral with respect to the Laplacian. More generally, our method allows us to construct an arbitrary number of isospectral but mutually non-diffeomorphic nilmanifolds. Finally, we present two nilmanifolds of different dimensions such that the short time heat trace expansions of the corresponding sub-Laplace operators coincide up to a term which vanishes to infinite order as time tends to zero.