论文标题
$ f（t，t_g）$重力的大爆炸核合成约束
Big Bang Nucleosynthesis constraints on $f(T,T_G)$ gravity
论文作者
论文摘要
我们面对$ f（t，t_g）$重力，有大爆炸核合成（BBN）要求。前者是使用扭转标量和在拉格朗尼亚语中的高斯式术语的电触电等效物获得的，从而导致了修改后的弗里德曼方程，其中额外的扭转项构成有效的黑暗能源部门。我们计算了由额外的扭转条款与$λ$ CDM范式相比，冻结温度$ t_f $的偏差。然后，我们强加了五个特定的$ f（t，t_g）$模型，并提取模型参数的约束，以便为了满足观察性BBN绑定的比率$ |ΔT_F/ T_F | $。正如我们发现的那样，在大多数模型中，所涉及的参数在其一般相对性值周围的狭窄窗口中界定，就像在幂律模型中，指数$ n $需要为$ n \ lyssim 0.5 $。然而，对数模型可以轻松满足模型参数大区域的BBN约束。该功能应在未来的模型构建中考虑到。
We confront $f(T,T_G)$ gravity, with Big Bang Nucleosynthesis (BBN) requirements. The former is obtained using both the torsion scalar, as well as the teleparallel equivalent of the Gauss-Bonnet term, in the Lagrangian, resulting to modified Friedmann equations in which the extra torsional terms constitute an effective dark energy sector. We calculate the deviations of the freeze-out temperature $T_f$, caused by the extra torsion terms in comparison to $Λ$CDM paradigm. Then we impose five specific $f(T,T_G)$ models and we extract the constraints on the model parameters in order for the ratio $|ΔT_f/ T_f|$ to satisfy the observational BBN bound. As we find, in most of the models the involved parameters are bounded in a narrow window around their General Relativity values as expected, as in the power-law model where the exponent $n$ needs to be $n\lesssim 0.5$. Nevertheless the logarithmic model can easily satisfy the BBN constraints for large regions of the model parameters. This feature should be taken into account in future model building.
