L 2 boundary decay properties of the heat kernel and spectral density. We deduce bounds on the rate of convergence of the eigenvalues when the region is slightly reduced in size. It is remarkable that several of the bounds do not involve the space dimension. AMS subject classifications: 35P99, 35P20, 47A75, 47B25 keywords: boundary decay, Laplacian, Hardy inequality, eigenfunctions, heat kernel...

The paper relates to possible connection between spectrum power-law decay and correlation dimension estimation for electroencephalogram (EEG). EEG signals recorded during relaxed wakefulness were analysed. Power-law decay of about 2.28 prevailing over the exponential falling off was established when exponent from the whole EEG spectrum was taken. The correlation dimension was also estimated. Th...

We discuss spectral representations of the Perron-Frobenius operator, U, associated with a highly chaotic map. The continuous spectrum of U does not contain (except coincidentally) information about physically accessible quantities such as decay rates of correlation functions. We show constructively that decay rates can be incorporated into a generalized spectral decomposition of U if its domai...

Remotely sensed estimates of crop residue cover (fR) are required to assess the extent of conservation tillage over large areas; the impact of decay processes on estimates of residue cover is unknown. Changes in wheat straw composition and spectral reflectance were measured during the decay process and their impact on estimates of fR were assessed. Proportions of cellulose and hemicellulose dec...

Using time-resolved single photon counting, fluorescence decay in photosystem I (PS I) was analyzed in mutant strains of Chlamydomonas reinhardtii that lack photosystem II. Two strains are compared: one with a wild-type PS I core antenna (120 chlorophyll a/P700) and a second showing an apparent reduction in core antenna size (60 chlorophyll a/P700). These data were calculated from the lifetimes...

This study presents a new frequency domain parameter, Parabolic Spectral Parameter (PSP), for the quantification of the glottal volume velocity waveform. PSP is based on fitting a parabolic function to the low-frequency part of a pitch-synchronously computed spectrum of the estimated glottal flow. PSP gives a single numerical value that describes how the spectral decay of an obtained glottal fl...

In He-like systems the decay of the 1s2s S0 excited state to the 1s S0 ground state is not allowed. This excited state can only decay to the ground state via the emission of two photons. The spectral shape of the emitted continuum is determined by the complete structure of the atomic system as all bound and continuum P states contribute to the 2E1 decay. For very heavy atomic systems the P stat...

Using only independent high-scale OPE input, we investigate QCD sum rule constraints on two currently incompatible versions of the isovector vector spectral function, one obtained from electroproduction (EM) data, the other from hadronic τ decay data. Sum rules involving weighted integrals over the spectral function, from threshold to a variable upper endpoint s0, are employed. It is shown that...

We propose a physical model of gamma-ray burst spectral evolution in which impulsively accelerated nonthermal leptons cool by saturated Compton upscattering of soft photons. This model naturally explains the recently discovered exponential decay of the spectral break energy with photon fluence, the hard-to-soft spectral evolution patterns, and other spectral and temporal properties of gamma-ray...