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arXiv 2408.02538gr-qcastro-ph.COhep-th
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$G_{3}$ —— 相互作用的标量-张量暗能量

$G_{3}$ -- interacting scalar tensor dark energy

Masroor C. Pookkillath, Nandan Roy

AI总结:

本研究在Horndeski理论的$G_3$项中加入相互作用,推导了背景和扰动方程,并利用遗传算法测试模型,比较$H(z)$和$f\sigma_{8}$数据,发现引力耦合被修改。

摘要:

我们研究了在Horndeski理论的$G_3$项中加入相互作用的效果,其中引力波的传播不被修改。我们从作用量出发推导了背景和扰动的运动方程。我们还推导了张量模式和标量模式传播的无鬼及拉普拉斯不稳定性条件。然后我们在准静态近似下研究了物质扰动的演化。我们发现,在该理论中,重子和冷暗物质过密度的引力耦合被修改。我们引入了理论中自由函数的一个具体模型,并研究了背景和线性扰动动力学。然后我们使用遗传算法来测试该模型。我们比较了模型的$H(z)$函数与遗传算法预测的$H(z)$曲线,使用了$H(z)$数据。对于扰动部分,我们计算了模型的$f\sigma_{8}$可观测量,并将其与遗传算法从$f\sigma_{8}$数据预测的函数进行比较。

英文摘要:

We study the effect of adding an interaction in the $G_3$ term of Horndeski theory, where the propagation of gravitational waves are not modified. We derive the background and perturbation equations of motion from the action. We also derive the no-ghost and Laplacian instability conditions for tensor modes and scalar mode propagation. Then we study the evolution of the matter perturbation in the quasi-static approximation. We find that the gravitational couplings to the baryonic and cold dark matter over density are modified in this theory. We introduce a concrete model of the free function in the theory and study the background and linear perturbation dynamics. We then use the genetic algorithm to test the model. We compare the $H(z)$ function of the model and the $H(z)$ curve predicted by the genetic algorithm, using the $H(z)$ data. For the perturbation sector we compute the $fσ_{8}$ observable for the model and compare it with the predicted function from the genetic algorithm from the $fσ_{8}$ data.

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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