Bony and Häfner have recently obtained positive commutator estimates on the Laplacian in the low-energy limit on asymptotically Euclidean spaces; these estimates can be used to prove local energy decay estimates if the metric is non-trapping. We simplify the proof of the estimates of Bony-Häfner and generalize them to the setting of scattering manifolds (i.e. manifolds with large conic ends), b...

In this paper we give a simple characterization of the Laplacian spectra of a family of graphs as the eigenvalues of symmetric tridiagonal matrices. In addition, we apply our result to obtain an upper and lower bounds for the Laplacian-energy-like invariant of these graphs. The class of graphs considered are obtained by copies of modified generalized Bethe trees (obtained by joining the vertice...

Buildings are one of the major energy consumers globally. The climate change and global warming symptoms increasing Green House Gases emis- sions because growing consumption. Majority electricity pro- duced from fossil fuels, coal, which source GHG emission. Here renewable efficient measure consumption reduction can give opportunity to do save our earth by reducing emission level. integrated so...