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arXiv 1506.06313astro-ph.COgr-qchep-th
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用宇宙剪切检验修正引力

Testing Modified Gravity with Cosmic Shear

Joachim Harnois-Déraps, Dipak Munshi, Patrick Valageas, Ludovic van Waerbeke, Philippe Brax, Peter Coles, Luca Rizzo

摘要:

我们使用的宇宙剪切数据从加拿大-法国-夏威夷望远镜透镜巡天放置约束的$f(R)$和{ \it广义膨胀}模型的修改的重力。这与其他探测器是高度互补的,因为约束主要来自非线性尺度:相对于广义相对论+ $Λ$ CDM场景的最大偏差发生在$k\sim1 h \mbox{Mpc}^{-1}$。在这些尺度下,有必要考虑已知的重子反馈和大质量中微子的简并,因此我们对这三种物理效应进行了联合约束。为了实现这一目标,我们制定这些修改后的重力理论在一个共同的层析参数化,我们计算它们的集群属性相对于GR宇宙的影响,并传播到弱透镜$ξ_{\pm}$量的观察到的修改。面对宇宙剪切数据,我们拒绝$f(R)$ $\{ |f_{R_0}|=10^{-4}, n=1\}$模型与超过99.9%的置信区间(CI)时,假设$Λ$ CDM暗物质的唯一模型。在重子反馈过程和总质量高达0.2eV的大质量中微子的存在下,模型在所有研究的不同组合中至少有94%CI是不利的。对$\{ |f_{R_0}|=10^{-4}, n=2\}$模型的约束较弱,但仍不利,至少有89% CI。我们确定了几个特定的组合中微子质量,重子反馈和$f(R)$或Dilaton引力模型,被排除在当前的宇宙剪切数据。值得注意的是,在所有研究过的修正引力方案中,具有三个无质量中微子且没有重子反馈的宇宙都是非常不利的。这些结果表明,竞争的约束可能会实现与未来的宇宙剪切数据。

英文摘要:

We use the cosmic shear data from the Canada-France-Hawaii Telescope Lensing Survey to place constraints on $f(R)$ and {\it Generalized Dilaton} models of modified gravity. This is highly complimentary to other probes since the constraints mainly come from the non-linear scales: maximal deviations with respects to the General-Relativity + $Λ$CDM scenario occurs at $k\sim1 h \mbox{Mpc}^{-1}$. At these scales, it becomes necessary to account for known degeneracies with baryon feedback and massive neutrinos, hence we place constraints jointly on these three physical effects. To achieve this, we formulate these modified gravity theories within a common tomographic parameterization, we compute their impact on the clustering properties relative to a GR universe, and propagate the observed modifications into the weak lensing $ξ_{\pm}$ quantity. Confronted against the cosmic shear data, we reject the $f(R)$ $\{ |f_{R_0}|=10^{-4}, n=1\}$ model with more than 99.9% confidence interval (CI) when assuming a $Λ$CDM dark matter only model. In the presence of baryonic feedback processes and massive neutrinos with total mass up to 0.2eV, the model is disfavoured with at least 94% CI in all different combinations studied. Constraints on the $\{ |f_{R_0}|=10^{-4}, n=2\}$ model are weaker, but nevertheless disfavoured with at least 89% CI. We identify several specific combinations of neutrino mass, baryon feedback and $f(R)$ or Dilaton gravity models that are excluded by the current cosmic shear data. Notably, universes with three massless neutrinos and no baryon feedback are strongly disfavoured in all modified gravity scenarios studied. These results indicate that competitive constraints may be achieved with future cosmic shear data.

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