Abstract Weak gravitational lensing by the intervening large-scale structure (LSS) of Universe is leading non-linear effect on anisotropies cosmic microwave background (CMB). The integrated line-of-sight mass that causes distortion — known as convergence can be reconstructed from lensed temperature and polarization via estimators quadratic in CMB modes, its power spectrum has been measured mult...

In this paper, we discuss the non-Guassianity originated from the α-vacuum on the CMB anisotropy. For α-vacuum, there exist correlation between points in the acausal two patches of de Sitter spactime. Such kind of correlation can lead to large local form non-Guassianity in α-vacuum. For the single field slowroll inflationary scenario, the spacetime is in a quasi-de Sitter phase during the infla...

We consider the long-standing problem of predicting the hierarchical clustering amplitudes Sp in the strongly non-linear regime of gravitational evolution. N-body results for the nonlinear evolution of the bispectrum (the Fourier transform of the three-point density correlation function) suggest a physically motivated ansatz that yields the strongly non-linear behavior of the skewness, S3, star...

The analysis and classification of electromyography (EMG) signals are very important in order to detect some symptoms of diseases, prosthetic arm/leg control, and so on. In this study, an EMG signal was analyzed using bispectrum, which belongs to a family of higher-order spectra. An EMG signal is the electrical potential difference of muscle cells. The EMG signals used in the present study are ...

A simple method is presented for the rapid simulation of statistically-isotropic non-Gaussian maps of CMB temperature fluctuations with a given power spectrum and analyticallycalculable bispectrum and higher-order polyspectra. The nth-order correlators of the pixel values may also be calculated analytically. The cumulants of the simulated map may be used to obtain an expression for the probabil...

We extend a previous bispectrum analysis of the Cosmic Microwave Background temperature anisotropy, allowing for the presence of correlations between different angular scales. We find a strong non-Gaussian signal in the “inter-scale” components of the bispectrum: their observed values concentrate close to zero instead of displaying the scatter expected from Gaussian maps. This signal is present...

In this article, a novel bicepstrum-based approach is suggested for ground moving radar target classification. Distinctive classification features were extracted from short-time backscattering bispectrum estimates of the micro-Doppler signature. Real radar data were obtained using surveillance Doppler microwave radar operating at 34 GHz. Classifier performance was studied in detail using the Ga...

Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the universe. We calculate quasilinear effects in the growth of structure in ƒ(R) models of gravity using perturbation theory. We find significant deviations in the bispectrum that depend on cosmic time, length scale and triangle shape. However the deviations in the reduced bis...

Galaxy power spectrum and bispectrum signals are distorted by peculiar velocities other relativistic effects arising from a perturbed spacetime background. In addition, study of correlation functions tracers in Fourier space is often done the plane-parallel approximation under which it assumed that line-of-sight (LOS) vectors parallel. this work we show simple perturbative procedure can be empl...