论文标题
GW170817和GRB 170817A的五维DS时段的半径限制
Constraint on the radius of five-dimensional dS spacetime with GW170817 and GRB 170817A
论文作者
论文摘要
最近对重力波（GW）事件GW170817及其电磁对应物GRB 170817A的检测是由二进制中子星（NS）合并产生的，这是多中途天文学的新里程碑。这两个信号之间的时间间隔吸引了物理学家的广泛关注。在Braneworld的情况下，GWS可以通过散装传播，而电磁波（EMW）则在棕褐色（即我们的宇宙）上界定。因此，GWS和EMW的轨迹可能遵循不同的路径。如果GWS和EMW是同时起源于Brane上同一来源的，则预计它们将连续到达观察者。因此，GW170817和GRB 170817A之间的时间延迟可能会携带额外维度的信息。在本文中，我们尝试在五维DS（$ \ text {ds} _5 $）时段的上下文中研究这种现象。我们首先研究了两个特殊的宇宙模型，即De Sitter和Einstein-De Sitter模型，并在每种情况下计算重力范围半径。对于真实的宇宙，我们将考虑$λ$ CDM型号。我们的结果表明，对于宇宙的De Sitter模型，$ \ text {ds} _5 $ radius无法促成时间延迟。有了观察数据的数据，我们将$ \ text {ds} _5 $半径限制为$ \ ell \ gtrsim7.5 \ gtrsim7.5 \ times10^{2} {2} \，\ \ \ text {tpc} $ for einstein-de sitter模型和$ \ ell \ ell \ grsim2.4 \ gtrsim2.4 \ text $ \ gtrsim2.4 \ text $ $λ$ CDM型号。在考虑了二进制NS合并的不同天体物理过程给出的源红移的不确定性和时间段之后，我们发现我们的约束对（0.005，0.01）的红移不敏感（0.005，0.01）和（-100s，1.734s）的范围（0.005，0.01）。
The recent detections of the gravitational wave (GW) event GW170817 and its electromagnetic counterpart GRB 170817A produced by a binary neutron star (NS) merger is a new milestone of multimessenger astronomy. The time interval between these two signals has attracted widespread attention from physicists. In the braneworld scenario, GWs could propagate through the bulk while electromagnetic waves (EMWs) are bounded on the brane, i.e., our Universe. Therefore, the trajectories of GWs and EMWs may follow different pathes. If GWs and EMWs are originated simultaneously from the same source on the brane, they are expected to arrive at the observer successively. Consequently, the time delay between GW170817 and GRB 170817A may carry the information of the extra dimension. In this paper, we try to investigate the phenomenon in the context of a five-dimensional dS ($\text{dS}_5$) spacetime. We first study two special Universe models, i.e., de Sitter and Einstein-de Sitter models, and calculate the gravitation horizon radius in each case. For the real Universe, we then consider the $Λ$CDM model. Our results show that for the de Sitter model of the Universe, the $\text{dS}_5$ radius could not contribute to the time delay. With the data of the observation, we constrain the $\text{dS}_5$ radius to $\ell\gtrsim7.5\times10^{2}\,\text{Tpc}$ for the Einstein-de Sitter model and $\ell\gtrsim2.4\times10^{3}\,\text{Tpc}$ for the $Λ$CDM model. After considering the uncertainty in the source redshift and the time-lags given by different astrophysical processes of the binary NS merger, we find that our constraints are not sensitive to the redshift in the range of (0.005, 0.01) and the time-lag in the range of (-100s, 1.734s).
