发表机构
Institut d’Astrophysique de Paris (IAP), CNRS, Sorbonne Université（巴黎天文物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文探讨脉冲星计时阵列探测到的引力波背景源于畴壁或一阶相变，其重子等曲率涨落可缓解氘矛盾，但过量则被排除。
AI 中文摘要
脉冲星计时阵列（PTAs）探测到了纳赫兹引力波背景，这通常归因于湮灭的畴壁（DWs）或一阶相变（FOPTs）。它们的再加热过程在重子-光子比中留下了涨落印记。这些所谓的重子等曲率涨落$S_B$一直存续到大爆炸核合成时期，而核合成的产额对其具有非线性依赖。因此，适度的$S_B$涨落可以缓解PTA优选区域部分区域当前的氘矛盾，从而增强其解释力。过量的DWs和过强的FOPTs会过度产生$D/H$，因而被排除。
英文摘要
Pulsar timing arrays (PTAs) have detected a nanohertz gravitational-wave background, often attributed to annihilating domain walls (DWs) or first-order phase transitions (FOPTs). Their reheating imprints fluctuations in the baryon-to-photon ratio. These so-called baryon isocurvature fluctuations $S_B$ survive until Big Bang Nucleosynthesis, whose yields depend nonlinearly on it. Modest $S_B$ fluctuations can therefore alleviate the current deuterium tension in parts of the PTA preferred regions and therefore strengthen their interpretation. Overabundant DWs and too strong FOPTs overproduce $D/H$ and are ruled out.
Comments5 pages, 2 Figures + 23 pages Appendix and 5 Figures
