Stellar dynamics in the periodic cube

التفاصيل البيبلوغرافية
العنوان: Stellar dynamics in the periodic cube
المؤلفون: Magorrian, John
المصدر: Monthly Notices of the Royal Astronomical Society, Volume 507, Issue 4, November 2021, Pages 4840-4851
سنة النشر: 2021
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Astrophysics of Galaxies
الوصف: We use the problem of dynamical friction within the periodic cube to illustrate the application of perturbation theory in stellar dynamics, testing its predictions against measurements from $N$-body simulation. Our development is based on the explicitly time-dependent Volterra integral equation for the cube's linear response, which avoids the subtleties encountered in analyses based on complex frequency. We obtain an expression for the self-consistent response of the cube to steady stirring by an external perturber. From this we show how to obtain the familiar Chandrasekhar dynamical friction formula and construct an elementary derivation of the Lenard--Balescu equation for the secular quasilinear evolution of an isolated cube composed of $N$ equal-mass stars. We present an alternative expression for the (real-frequency) van Kampen modes of the cube and show explicitly how to decompose any linear perturbation of the cube into a superposition of such modes.
Comment: 13 pages. References added to match accepted version
نوع الوثيقة: Working Paper
DOI: 10.1093/mnras/stab2457
URL الوصول: http://arxiv.org/abs/2106.10178
رقم الأكسشن: edsarx.2106.10178
قاعدة البيانات: arXiv