In this work,we study a direction dependent power spectrum in anisotropic Finsler spacetime. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. The angular powe...In this work,we study a direction dependent power spectrum in anisotropic Finsler spacetime. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. The angular power spectrum of the temperature fluctuations has a lower amplitude in comparison to the ΛCDM model in the multipole range l = 2-40. Our theoretical model gives a correction to the isotropic angular power spectrum Cl^TT ldue to the breaking of rotational invariance of the primordial power spectrum. We estimate best-fit model parameters along with the six ΛCDM cosmological parameters using the PLANCK likelihood code in Cosmo MC software. We find that this modified angular power spectrum fits the CMB temperature data in the multipole range l = 2-10 to a good extent but fails for the whole multipole range l = 2-40.展开更多
We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background （CMB） with the Wilkinson Microwave Anisotropy Probe （WMAP） data and model the large-angle anomalies as the effect of the C...We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background （CMB） with the Wilkinson Microwave Anisotropy Probe （WMAP） data and model the large-angle anomalies as the effect of the CMB quadrupole anisotropies caused by the local density inhomogeneities. The quadrupole caused by the local density inhomogeneities is different from the special relativity kinematic quadrupole. If the observer inhabits a strong inhomogeneous region, the lo- cal quadrupole should not be neglected. We calculate such local quadrupole under the assumption that there is a huge density fluctuation field in the direction （284°, 74°）, where the density fluctuation is 10-3, and its center is - 112 h-1 Mpc away from us. After removing such mock signals from WMAP data, the power in the quadrupole, C2, increases from the range （200 - 260 μK2） to - 1000 μK2. The quantity S, which is used to estimate the alignment between the quadrupole and the octopole, decreases from （0.7 - 0.74） to （0.31 - 0.37）, while the model predicts that C2 = 1071.5 μK2, and S = 0.412. So our local density inhomogeneity model can, in part, explain the WMAP low-l anomalies.展开更多
基金funded by the National Natural Science Foundation of China (Grant Nos.11375203,11675182 and 11690022)
文摘In this work,we study a direction dependent power spectrum in anisotropic Finsler spacetime. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. The angular power spectrum of the temperature fluctuations has a lower amplitude in comparison to the ΛCDM model in the multipole range l = 2-40. Our theoretical model gives a correction to the isotropic angular power spectrum Cl^TT ldue to the breaking of rotational invariance of the primordial power spectrum. We estimate best-fit model parameters along with the six ΛCDM cosmological parameters using the PLANCK likelihood code in Cosmo MC software. We find that this modified angular power spectrum fits the CMB temperature data in the multipole range l = 2-10 to a good extent but fails for the whole multipole range l = 2-40.
文摘We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background （CMB） with the Wilkinson Microwave Anisotropy Probe （WMAP） data and model the large-angle anomalies as the effect of the CMB quadrupole anisotropies caused by the local density inhomogeneities. The quadrupole caused by the local density inhomogeneities is different from the special relativity kinematic quadrupole. If the observer inhabits a strong inhomogeneous region, the lo- cal quadrupole should not be neglected. We calculate such local quadrupole under the assumption that there is a huge density fluctuation field in the direction （284°, 74°）, where the density fluctuation is 10-3, and its center is - 112 h-1 Mpc away from us. After removing such mock signals from WMAP data, the power in the quadrupole, C2, increases from the range （200 - 260 μK2） to - 1000 μK2. The quantity S, which is used to estimate the alignment between the quadrupole and the octopole, decreases from （0.7 - 0.74） to （0.31 - 0.37）, while the model predicts that C2 = 1071.5 μK2, and S = 0.412. So our local density inhomogeneity model can, in part, explain the WMAP low-l anomalies.
