标题： de Sitter中的四极辐射：位移记忆和Bondi度规 显示英文标题

标题： Quadrupolar radiation in de Sitter: Displacement memory and Bondi metric

摘要： 我们得到了物质源在哈勃尺度以下产生的德西特时空度规扰动的闭形式表达式，该表达式在多极展开中直到四极阶，在广义谐波规范和邦迪规范中均被考虑，包括两种宇称（即质量四极子和电流四极子）。 我们证明了这种源在接近未来无穷远处会引起位移记忆效应，该效应起源于偶数宇称部分，来自未来无穷远两个非辐射区域之间的$\Lambda$-BMS 转变。 显示英文摘要

摘要： We obtain the closed form expression for the metric perturbation around de Sitter spacetime generated by a matter source below Hubble scale both in generalized harmonic gauge and in Bondi gauge up to quadrupolar order in the multipolar expansion, including both parities (i.e. both mass and current quadrupoles). We demonstrate that such a source causes a displacement memory effect close to future infinity that originates, in the even-parity sector, from a $\Lambda$-BMS transition between the two non-radiative regions of future infinity.