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arXiv 2602.17154gr-qcastro-ph.HE
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Schwarzschild-德西特时空中的极端质量比 inspirals I:弱场轨道

Extreme-mass ratio inspirals in Schwarzschild - de Sitter spacetime I: Weak-field orbits

National Institute of Physics, University of the Philippines(菲律宾大学国家物理研究所)

John Adrian N. Villanueva, Ian Vega

AI总结:

研究极端质量比轨道在Schwarzschild-德西特时空中的演化,分析SdS参数对轨道圆化、 plunge时间及波形的影响,探讨环境耦合对引力波天文观测的潜在影响。

摘要:

紧凑天体向黑洞进化的过程是未来空间探测器如LISA探测低频引力波的关键来源。尽管相关模型已取得显著进展,但通常局限于渐近平坦时空。本文研究渐近平坦性偏离对亚稳态轨道演化的改变。使用Schwarzschild-德西特度规,通过SdS参数(λ)参数化这些偏离,并分析其对束缚轨道的影响。计算λ如何改变束缚与 plunge状态的分隔线,并修改二体系统能量、角动量和轨道几何的关系。通过弱场极限下的修正四极子公式,研究λ对圆化、 plunge时间及轨道轨迹的影响。证明正SdS参数加速偏心率衰减并缩短进动时间尺度。此外,生成受辐射反应影响的亚稳波形,显示由λ引起的振幅增加和累积相位提前。虽然严格宇宙学λ效果微乎其微,但若λ作为天文环境代理则可能对观测相关性产生影响。结果表明,此类环境耦合可能显著偏移事件率估计和波形模板。

英文摘要:

The inspiral of a compact object into a black hole is a key source of low - frequency gravitational waves for future space-based detectors like LISA. While models of this process have advanced considerably, they typically focus on asymptotically flat spacetimes. In this paper, we investigate how departures from asymptotic flatness, whether driven by cosmic expansion or large-scale galactic environments, alter adiabatic orbital evolution. Using the Schwarzschild - de Sitter (SdS) metric, we parametrize these deviations via an `SdS parameter' ($λ$) and analyze its impact on bound orbits. We calculate how $λ$ shifts the separatrix between bound and plunging states and modifies the relationship between a binary's energy, angular momentum, and orbital geometry. By applying a modified quadrupole formula in the weak-field limit, we investigate the effect of $λ$ on circularization, plunge times, and orbital trajectories. We show that a positive SdS parameter accelerates eccentricity decay and shortens inspiral timescales. We also generate adiabatic waveforms from inspirals evolving under radiation reaction, exhibiting an increase in amplitude and a cumulative phase advance induced by $λ$. While these effects are negligible if $λ$ is strictly cosmological, they become observationally relevant if the parameter serves as a proxy for astrophysical environments that induce $\sim r^2$ potential corrections. Our results suggest that such environmental coupling could meaningfully bias event rate estimates and waveform templates for space-based gravitational-wave astronomy.

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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