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arXiv 0905.3383astro-ph.CO
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基于Fisher矩阵分解的暗能量预测

Fisher Matrix Decomposition for Dark Energy Prediction

T. D. Kitching, A. Amara

摘要:

在限制暗能量状态方程w(z)展开的情况下,我们证明了Fisher矩阵的本征分解对展开的最大阶数和基组的选择都很敏感。我们研究了特定函数在某个基集中展开的情况下的Fisher矩阵形式。作为一个例子,我们显示了一个全天弱透镜层析实验的结果。我们证明了本征函数的集合不是唯一的,并且最佳约束函数仅在非常高阶的N > 100时才能精确地再现,tophat基组需要更高阶。我们发现,常用的方法用于寻找边缘化特征函数的错误是敏感的非w(z)参数和先验的选择。Fisher矩阵的特征分解是一个潜在的有用工具,可以用来确定实验可以约束w(z)的预测精度。它还允许重建实验对w(z)变化的红移灵敏度。然而,该技术是敏感的顺序和基组的选择。公开可用的代码可作为iCosmo的一部分在http://www.icosmo.org上获得。

英文摘要:

Within the context of constraining an expansion of the dark energy equation of state w(z) we show that the eigendecomposition of Fisher matrices is sensitive to both the maximum order of the expansion and the basis set choice. We investigate the Fisher matrix formalism in the case that a particular function is expanded in some basis set. As an example we show results for an all sky weak lensing tomographic experiment. We show that the set of eigenfunctions is not unique and that the best constrained functions are only reproduced accurately at very higher order N > 100, a tophat basis set requires an even higher order. We show that the common approach used for finding the marginalised eigenfunction errors is sensitive to the choice of non-w(z) parameters and priors. The eigendecomposition of Fisher matrices is a potentially useful tool that can be used to determine the predicted accuracy with which an experiment could constrain w(z). It also allows for the reconstruction of the redshift sensitivity of the experiment to changes in w(z). However the technique is sensitive to both the order and the basis set choice. Publicly available code is available as part of iCosmo at http://www.icosmo.org .

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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