Gravitational instability of polytropic spheres and generalized thermodynamics

نویسندگان

چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Gravitational instability of polytropic spheres and generalized thermodynamics

We complete the existing literature on the structure and stability of polytropic gas spheres reported in the classical monograph of Chandrasekhar (1942). For isolated polytropes with index 1 < n < 5, we provide a new, alternative, proof that the onset of instability occurs for n = 3 and we express the perturbation profiles of density and velocity at the point of marginal stability in terms of t...

متن کامل

Gravitational instability of isothermal and polytropic spheres

We complete previous investigations on the thermodynamics of self-gravitating systems by studying the grand canonical, grand microcanonical and isobaric ensembles. We also discuss the stability of polytropic spheres in connexion with a generalized thermodynamical approach proposed by Tsallis. We determine in each case the onset of gravitational instability by analytical methods and graphical co...

متن کامل

Gravitational instability of finite isothermal spheres

We investigate the stability of bounded self-gravitating systems in the canonical ensemble by using a thermodynamical approach. Our study extends the earlier work of Padmanabhan [ApJ Supp. 71, 651 (1989)] in the microcanonical ensemble. By studying the second variations of the free energy, we find that instability sets in precisely at the point of minimum temperature in agreement with the theor...

متن کامل

Gravitational instability of slowly rotating isothermal spheres

We discuss the statistical mechanics of rotating self-gravitating systems by allowing properly for the conservation of angular momentum. We study analytically the case of slowly rotating isothermal spheres by expanding the solutions of the Boltzmann-Poisson equation in a series of Legendre polynomials, adapting the procedure introduced by Chandrasekhar (1933) for distorted polytropes. We show h...

متن کامل

Reexamination of polytropic spheres in Palatini fðRÞ gravity

We investigate spherically symmetric, static matter configurations with polytropic equation of state for a class of fðRÞmodels in Palatini formalism and show that the surface singularities recently reported in the literature are not physical in the case of Planck scale modified Lagrangians. In such cases, they are just an artifact of the idealized equation of state used. In fact, we show that f...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Astronomy & Astrophysics

سال: 2002

ISSN: 0004-6361,1432-0746

DOI: 10.1051/0004-6361:20020306