We construct, for the first time, the time-domain gravitational wave strain waveform from the collapse of a strongly gravitating Abelian Higgs cosmic string loop in full general relativity. We show that the strain exhibits a large memory effect during merger, ending with a burst and the characteristic ringdown as a black hole is formed. Furthermore, we investigate the waveform and energy emitted as a function of string width, loop radius and string tension $G\mu$. We find that the mass normalized gravitational wave energy displays a strong dependence on the inverse of the string tension $E_{\mathrm{GW}}/M_0\propto 1/G\mu$, with $E_{\mathrm{GW}}/M_0 \sim {\cal O}(1)\%$ at the percent level, for the regime where $G\mu\gtrsim10^{-3}$. Conversely, we show that the efficiency is only weakly dependent on the initial string width and initial loop radii. Using these results, we argue that gravitational wave production is dominated by kinematical instead of geometrical considerations.

中文翻译：

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来自宇宙弦环的相干引力波形和记忆

我们首次在完全广义相对论中构建了强引力阿贝尔希格斯宇宙弦环坍塌的时域引力波应变波形。我们表明，该应变在合并过程中表现出很大的记忆效应，以爆发结束，并在形成黑洞时出现特征性的衰减。此外，我们研究了作为弦宽、环半径和弦张力 $G\mu$ 的函数发射的波形和能量。我们发现质量归一化引力波能量对弦张力的倒数 $E_{\mathrm{GW}}/M_0\propto 1/G\mu$ 表现出很强的依赖性，其中 $E_{\mathrm{GW}} /M_0 \sim {\cal O}(1)\%$ 在百分比级别，对于 $G\mu\gtrsim10^{-3}$ 的制度。相反，我们表明效率仅微弱地依赖于初始字符串宽度和初始循环半径。