{"title":"流不稳定性的物理机制","authors":"Nathan Magnan, Tobias Heinemann, Henrik N. Latter","doi":"arxiv-2408.07441","DOIUrl":null,"url":null,"abstract":"The main hurdle of planet formation theory is the metre-scale barrier. One of\nthe most promising ways to overcome it is via the streaming instability (SI).\nUnfortunately, the mechanism responsible for the onset of this instability\nremains mysterious. It has recently been shown that the SI is a Resonant Drag\nInstability (RDI) involving inertial waves. We build on this insight and\nclarify the physical picture of how the SI develops, while bolstering this\npicture with transparent mathematics. Like all RDIs, the SI is built on a\nfeedback loop: in the `forward action', an inertial wave concentrates dust into\nclumps; in the `backward reaction', those drifting dust clumps excite an\ninertial wave. Each process breaks into two mechanisms, a fast one and a slow\none. At resonance, each forward mechanism can couple with a backward mechanism\nto close a feedback loop. Unfortunately, the fast-fast loop is stable, so the\nSI uses the fast-slow and slow-fast loops. Despite this last layer of\ncomplexity, we hope that our explanation will help understand how the SI works,\nin which conditions it can grow, how it manifests itself, and how it saturates.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"27 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The physical mechanism of the streaming instability\",\"authors\":\"Nathan Magnan, Tobias Heinemann, Henrik N. Latter\",\"doi\":\"arxiv-2408.07441\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The main hurdle of planet formation theory is the metre-scale barrier. One of\\nthe most promising ways to overcome it is via the streaming instability (SI).\\nUnfortunately, the mechanism responsible for the onset of this instability\\nremains mysterious. It has recently been shown that the SI is a Resonant Drag\\nInstability (RDI) involving inertial waves. We build on this insight and\\nclarify the physical picture of how the SI develops, while bolstering this\\npicture with transparent mathematics. Like all RDIs, the SI is built on a\\nfeedback loop: in the `forward action', an inertial wave concentrates dust into\\nclumps; in the `backward reaction', those drifting dust clumps excite an\\ninertial wave. Each process breaks into two mechanisms, a fast one and a slow\\none. At resonance, each forward mechanism can couple with a backward mechanism\\nto close a feedback loop. Unfortunately, the fast-fast loop is stable, so the\\nSI uses the fast-slow and slow-fast loops. Despite this last layer of\\ncomplexity, we hope that our explanation will help understand how the SI works,\\nin which conditions it can grow, how it manifests itself, and how it saturates.\",\"PeriodicalId\":501270,\"journal\":{\"name\":\"arXiv - PHYS - Geophysics\",\"volume\":\"27 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Geophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.07441\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.07441","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
行星形成理论的主要障碍是米级壁垒。不幸的是,导致这种不稳定性发生的机制仍然很神秘。最近的研究表明,流不稳定性是一种涉及惯性波的共振阻力不稳定性(RDI)。我们以这一见解为基础,阐明了 SI 如何发展的物理图景,同时用透明的数学来支持这一图景。与所有 RDI 一样,SI 建立在反馈回路之上:在 "前向作用 "中,惯性波将尘埃集中成团;在 "后向反应 "中,这些漂移的尘埃团块激发惯性波。每个过程都分为快速和慢速两种机制。在共振时,每个前向机制都可以与一个后向机制耦合,从而形成一个反馈回路。不幸的是,"快-快 "环路是稳定的,因此,SI 使用了 "快-慢 "和 "慢-快 "环路。尽管还有最后一层复杂性,但我们希望我们的解释将有助于理解 SI 的工作原理、它在哪些条件下可以增长、它是如何表现出来的以及它是如何达到饱和的。
The physical mechanism of the streaming instability
The main hurdle of planet formation theory is the metre-scale barrier. One of
the most promising ways to overcome it is via the streaming instability (SI).
Unfortunately, the mechanism responsible for the onset of this instability
remains mysterious. It has recently been shown that the SI is a Resonant Drag
Instability (RDI) involving inertial waves. We build on this insight and
clarify the physical picture of how the SI develops, while bolstering this
picture with transparent mathematics. Like all RDIs, the SI is built on a
feedback loop: in the `forward action', an inertial wave concentrates dust into
clumps; in the `backward reaction', those drifting dust clumps excite an
inertial wave. Each process breaks into two mechanisms, a fast one and a slow
one. At resonance, each forward mechanism can couple with a backward mechanism
to close a feedback loop. Unfortunately, the fast-fast loop is stable, so the
SI uses the fast-slow and slow-fast loops. Despite this last layer of
complexity, we hope that our explanation will help understand how the SI works,
in which conditions it can grow, how it manifests itself, and how it saturates.