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arXiv 1205.1908astro-ph.CO
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用当前和未来数据检验距离对偶关系

Testing the distance duality relation with present and future data

Vincenzo F. Cardone, Susanna Spiro, Isobel Hook, Roberto Scaramella

摘要:

“光沿着时空度规的零测地线传播”和“光子数沿着光路守恒”的假设导致了距离对偶关系(DDR),$η= D_L(z) (1 + z)^{-2}/D_A(z) = 1$,其中$D_L(z)$和$D_A(z)$是到红移$z$的源的光度和角直径距离。为了检验DDR,我们遵循通常的策略,将由X射线和射电数据推断的一组星团的角直径距离与相同星团红移处的光度距离进行比较,使用局部回归技术从Ia型超新星(SNeIa)哈勃图估计$D_L(z)$。为了加强对DDR的约束,并摆脱与未知的集群几何形状的系统学,我们还调查了使用重子声学振荡(BAO)推断$D_A(z)$从未来的BAO调查的可能性。作为一个测试案例,我们认为建议的欧几里得任务调查的精度可以提供$η(z)$从预期的SNeIa和BAO数据。我们发现,BAO和本地回归耦合的组合允许减少$η_a = dη/dz|_{z = 0}$上的错误的一个因素,如果一个$η_0 = η(z = 0) = 1$是被迫的,并使用未来的数据。另一方面,虽然$η_0$的统计误差没有显著减少,但由于系统学影响的减少,对该数量的限制将得到改善。

英文摘要:

The assumptions that "light propagates along null geodesics of the spacetime metric" and "the number of photons is conserved along the light path" lead to the distance duality relation (DDR), $η= D_L(z) (1 + z)^{-2}/D_A(z) = 1$, with $D_L(z)$ and $D_A(z)$ the luminosity and angular diameter distances to a source at redshift $z$. In order to test the DDR, we follow the usual strategy comparing the angular diameter distances of a set of clusters, inferred from X - ray and radio data, with the luminosity distance at the same cluster redshift using the local regression technique to estimate $D_L(z)$ from Type Ia Supernovae (SNeIa) Hubble diagram. In order to both strengthen the constraints on the DDR and get rid of the systematics related to the unknown cluster geometry, we also investigate the possibility to use Baryon Acoustic Oscillations (BAO) to infer $D_A(z)$ from future BAO surveys. As a test case, we consider the proposed Euclid mission investigating the precision can be afforded on $η(z)$ from the expected SNeIa and BAO data. We find that the combination of BAO and the local regression coupled allows to reduce the errors on $η_a = dη/dz|_{z = 0}$ by a factor two if one $η_0 = η(z = 0) = 1$ is forced and future data are used. On the other hand, although the statistical error on $η_0$ is not significantly reduced, the constraints on this quantity will be nevertheless ameliorated thanks to the reduce impact of systematics.

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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