标题： 宇宙半球不对称性导致的宇宙学参数的方向依赖性 显示英文标题

标题： Direction dependence of cosmological parameters due to cosmic hemispherical asymmetry

摘要： 宇宙微波背景（CMB）温度场中存在持续的证据表明，在由WMAP以及PLANCK观测到的宇宙中存在半球不对称性，这增加了该不对称性具有宇宙学起源的可能性。这种信号的存在可能导致标准宇宙学模型参数在不同方向上具有不同的值，这对使用这些参数的其他研究可能具有重要意义。 我们通过注入既依赖于尺度又不依赖于尺度调制强度的非各向同性高斯随机模拟，研究了这种宇宙半球不对称性对宇宙学参数的影响。 我们的分析表明，对于所研究的这种各向异性破坏现象，$A_s$和$n_s$是最容易在天空中获得位置依赖性的参数。 正如预期的那样，我们发现对于CMB各向异性独立于尺度的调制情况，变化最大。 我们发现，与各向同性CMB天空的估计值相比，PLANCK数据中观察到的依赖于尺度的调制轮廓可能导致$A_s$的$1.25\sigma$偏差。 显示英文摘要

摘要： Persistent evidence for a cosmic hemispherical asymmetry in the temperature field of cosmic microwave background (CMB) as observed by both WMAP as well as PLANCK increases the possibility of its cosmological origin. Presence of this signal may lead to different values for the standard model cosmological parameters in different directions, and that can have significant implications for other studies where they are used. We investigate the effect of this cosmic hemispherical asymmetry on cosmological parameters using non-isotropic Gaussian random simulations injected with both scale dependent and scale independent modulation strengths. Our analysis shows that $A_s$ and $n_s$ are the most susceptible parameters to acquire position dependence across the sky for the kind of isotropy breaking phenomena under study. As expected, we find maximum variation arises for the case of scale independent modulation of CMB anisotropies. We find that scale dependent modulation profile as seen in PLANCK data could lead to only $1.25\sigma$ deviation in $A_s$ in comparison to its estimate from isotropic CMB sky.