标题： 向可能解决哈勃张力的霍恩德斯基引力迈进 显示英文标题

标题： Towards a possible solution to the Hubble tension with Horndeski gravity

摘要： 哈勃张力指的是从宇宙微波背景观测中推断出的哈勃常数$H_0$的值，假设宇宙的协调$\Lambda$CDM 模型，与从距离阶梯和其他直接测量中得到的哈勃常数之间的差异。 为了缓解这种张力，我们在一种最一般的标量-张量理论——霍恩德斯基引力框架内构建了一个合理的暗能量情景。 在我们的设置中，我们包含了动态暗能量标量场的自相互作用和非最小耦合，这些使得非常有趣的动力学行为出现，在低红移处表现出伪态行为，同时在高红移处具有负的暗能量密度。 这两个特征共同使该模型成为缓解哈勃张力的一个有希望的情景，只要适当选择模型参数。 为了实现一致的模型构建，我们证明该设置也免除了梯度不稳定性和鬼魂不稳定性。 最后，我们将该模型的预测与来自潘多拉、SH0ES、宇宙时钟和BAO的低红移观测进行对比，以获得模型参数的最佳拟合约束。 显示英文摘要

摘要： The Hubble tension refers to the discrepancy in the value of the Hubble constant $H_0$ inferred from the cosmic microwave background observations, assuming the concordance $\Lambda$CDM model of the Universe, and that from the distance ladder and other direct measurements. In order to alleviate this tension, we construct a plausible dark energy scenario, within the framework of Horndeski gravity which is one of the most general scalar-tensor theories yielding second-order equations. In our set-up, we include the self-interactions and nonminimal coupling of the dynamical dark energy scalar field which enable very interesting dynamics leading to a phantom behaviour at low redshifts along with negative dark energy densities at high redshifts. These two features together make this model a promising scenario to alleviate the Hubble tension for appropriate choices of the model parameters. Towards a consistent model building, we show that this set-up is also free from both the gradient and ghost instabilities. Finally, we confront the predictions of the model with low redshift observations from Pantheon, SH0ES, cosmic chronometers and BAO, to obtain best fit constraints on model parameters.