We consider the energy current correlation function for the FPU-β lattice. For small non-linearity one can rely on kinetic theory. The issue reduces then to a spectral analysis of the linearized collision operator. We prove thereby that, on the basis of kinetic theory, the energy current correlations decay in time as t−3/5. It follows that the thermal conductivity is anomalous, increasing as N ...

Using the Riesz basis approach, we study a sandwich beam that is composed of an outer stiff layer and a compliant middle layer. The dynamic behavior and analyticity of the system are obtained based on a detailed spectral analysis and Riesz basis generation. As a consequence, the analyticity of the solution and the exponential stability of the system are concluded.

This paper presents an analysis of variable outputs in the speech of English-, Spanishand Catalanspeaking 2 year-olds, to evaluate the evidence for multiple targets. Temporal analysis shows syllable duration is determined by actual segmental composition, compatible with either multiple targets or a process of categorical deletion. However, spectral analysis suggests deletions may be ‘gradient’,...

We consider the problem of learning regression functions from pairwise data when there exists prior knowledge that the relation to be learned is symmetric or anti-symmetric. Such prior knowledge is commonly enforced by symmetrizing or anti-symmetrizing pairwise kernel functions. Through spectral analysis, we show that these transformations reduce the kernel’s effective dimension. Further, we pr...

We investigate a modification in the action of inflaton due to noncommutativity leads to a nonstandard initial vacuum and oscillatory corrections in the initial power spectrum. We show that the presence of these oscillations causes a drop in the WMAP χ2 about ∆χ2 ∼ 8.5. We also show that this nonstandard initial vacuum state can provide a rolling in cosmological constant. As a bonus, from the p...

A new algorithm is presented for adaptive comb filtering and parametric spectral estimation of harmonic signals with additive white noise. The algorithm is composed of two cascaded parts. The first estimates the fundamental frequency and enhances the harmonic component in the input, and the second estimates the harmonic amplitudes and phases. Performance analysis provides new results for the as...

Most of economic and financial time series have a nonstationary behavior. There are different types of nonstationary processes, such as those with stochastic trend and those with deterministic trend. In practice, it can be quite difficult to distinguish between the two processes. In this paper, we compare random walk and determinist trend processes using sample autocorrelation, sample partial a...

In this paper we are concerned with the spectral analysis of the sequence of preconditioned matrices {P−1 n An(a, m1,m2, k)}n, where n = (n1, n2), N(n) = n1n2 and where An(a, m1, m2 , k) ∈ RN(n)×N(n) is the symmetric two-level matrix coming from a high–order Finite Difference (FD) discretization of the problem

In this paper, the problem of carrier synchronization of OFDM systems in the presence of a substantial frequency offset is considered. New frequency estimation algorithms for the data aided (DA) mode are presented. The resulting two stage structure is able to cope with frequency offsets in the order of mukbles of the spacing between subchannels. Key features of the novel scheme W ~ i c h are pr...