Spherically symmetric collapse: initial configurations
Bayona E. Quevedo H. Alcubierre M.
18 April 2025Institute of Physics
Classical and Quantum Gravity
2025#42Issue 8
The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using a priori given equations of state that describe the matter as a perfect fluid. We propose an alternative approach, in which the energy density of the perfect fluid is given as a polynomial function of the radial coordinate that is well-behaved everywhere inside the fluid. We then solve the corresponding differential equations, including the Tolman-Oppenheimer-Volkoff equilibrium condition, using a fourth-order Runge-Kutta method and obtain a consistent model with a central perfect-fluid core surrounded by dust. We analyze the Hamiltonian constraint, the mass-to-radius relation, the boundary and physical conditions, and the stability and convergence properties of the numerical solutions. The energy density and pressure of the resulting matter distribution satisfy the standard physical conditions. The model is also consistent with the Buchdahl limit and the speed of sound conditions, even by using realistic values of compact astrophysical objects such as neutron stars.
neutron stars , perfect fluids , spherical symmetry , Tolman-Oppenheimer-Volkoff equation
Text of the article Перейти на текст статьи
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
Dipartimento di Fisica and Icra, Università di Roma ‘La Sapienza’, Roma, Italy
Al-Farabi Kazakh National University, Al-Farabi av. 71, Almaty, 050040, Kazakhstan
Instituto de Ciencias Nucleares
Dipartimento di Fisica and Icra
Al-Farabi Kazakh National University
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026