论文标题
使用Low-Z Galaxy调查数据来约束$ g _ {\ rm eff} $的晚期过渡
Constraining a late time transition of $G_{\rm eff}$ using low-z galaxy survey data
论文作者
论文摘要
最近指出的是，在最近的红移$ z_t $上进行了引力过渡，从而将有效的重力常数$ g _ {\ rm eff} $减少了约$ 10 \％$ $ $ $ $ $ z> z_t $，有可能导致$ z_tensensive $ z__t \ yssim 0.001 $。由于$ h（z）^2 \ sim g _ {\ rm eff} $，因此这种过渡也会导致哈勃图的斜率在$ z = z_t $时急剧变化，并且在$ z_t $ $ z_t $的每个红移箱的星系箱数量急剧下降。在这里，我们尝试通过使用两个可靠的低Z红移调查数据集（$ z <0.01 $）对这种过渡施加限制，该数据集（$ z <0.01 $）取自六度野外星系调查（6DFGS）以及2量质量红移调查（2MRS）。在这两项调查中，我们都以红移箱为单位，并专注于每个垃圾箱中的星系数（$Δn（z_i）$）。我们观察到两个数据集中大约20 mpc的星系的分布峰值。该特征可以归因于银河系的波动，星系的相干奇特速度或同一时代的超级晚期引力过渡。在后面的情况下，我们表明，该功能可能是由于$ g _ {\ rm eff} $的急剧变化而引起的，$Δg_ {\ rm eff}/g _ {\ rm eff} \ rm eff} \ simeq 0.6 $ at $ z_t \ simeq 0.005 $。因此，在保守的方法中，该方法可用于对在非常低的红移下发生的重力常数可能突然变化施加约束。
It has recently been pointed out that a gravitational transition taking place at a recent redshift $z_t$, reducing the effective gravitational constant $G_{\rm eff}$ by about $10\%$ for $z>z_t$, has the potential to lead to a resolution of the Hubble tension if $z_t\lesssim 0.01$. Since $H(z)^2\sim G_{\rm eff}$, such a transition would also lead to sharp change of the slope of the Hubble diagram at $z=z_t$ and a sharp decrease in the number of galaxies per redshift bin at $z_t$. Here we attempt to impose constraints on such a transition by using two robust low-z redshift survey datasets ($z<0.01$), taken from the Six-degree Field Galaxy Survey (6dFGS) as well as the 2MASS Redshift Survey (2MRS). In both surveys, we bin the data in redshift bins and focus on the number of galaxies in each bin ($ΔN(z_i)$). We observe a peak in the distribution of galaxies near a distance of approximately 20 Mpc in both datasets. This feature could be attributed to galactic density fluctuations, to coherent peculiar velocities of galaxies or to an ultra late-time gravitational transition in the same era. In the context of the later scenario we show that this feature could have been induced by a sharp change of $G_{\rm eff}$ by $ΔG_{\rm eff}/G_{\rm eff} \simeq 0.6$ at $z_t\simeq 0.005$. Thus, in a conservative approach, this method can be used to impose constraints on a possible abrupt change of the gravitational constant taking place at very low redshifts.
