44,023 research outputs found

    Primordial power spectrum of tensor perturbations in Finsler spacetime

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    We first investigate the gravitational wave in the flat Finsler spacetime. In the Finslerian universe, we derive the perturbed gravitational field equation with tensor perturbations. The Finslerian background spacetime breaks rotational symmetry and induces parity violation. Then we obtain the modified primordial power spectrum of tensor perturbations. The parity violation feature requires that the anisotropic effect contributes to TT,TE,EE,BBTT,TE,EE,BB angular correlation coefficients with l′=l+1l'=l+1 and TB,EBTB,EB with l′=ll'=l. The numerical results show that the anisotropic contributions to angular correlation coefficients depend on mm, and TETE and ETET angular correlation coefficients are different.Comment: 15 pages, 12 fugures. arXiv admin note: text overlap with arXiv:1502.0225

    Pushing towards the Limit of Sampling Rate: Adaptive Chasing Sampling

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    Measurement samples are often taken in various monitoring applications. To reduce the sensing cost, it is desirable to achieve better sensing quality while using fewer samples. Compressive Sensing (CS) technique finds its role when the signal to be sampled meets certain sparsity requirements. In this paper we investigate the possibility and basic techniques that could further reduce the number of samples involved in conventional CS theory by exploiting learning-based non-uniform adaptive sampling. Based on a typical signal sensing application, we illustrate and evaluate the performance of two of our algorithms, Individual Chasing and Centroid Chasing, for signals of different distribution features. Our proposed learning-based adaptive sampling schemes complement existing efforts in CS fields and do not depend on any specific signal reconstruction technique. Compared to conventional sparse sampling methods, the simulation results demonstrate that our algorithms allow 46%46\% less number of samples for accurate signal reconstruction and achieve up to 57%57\% smaller signal reconstruction error under the same noise condition.Comment: 9 pages, IEEE MASS 201
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