Kinetic theory of Jean instability in Eddington-inspired Born–Infeld gravity

Abstract

We analyze the stability of self-gravitating systems which dynamics is investigated using the collisionless Boltzmann equation, and the modified Poisson equation of Eddington-inspired Born-Infield gravity. These equations provide a description of the Jeans paradigm used to determine the critical scale above which such systems collapse. At equilibrium, the systems are described using the time-independent Maxwell-Boltzmann distribution function f 0 (v). Considering small perturbations to this equilibrium state, we obtain a modified dispersion relation, and we find a new characteristic scale length. Our results indicate that the dynamics of self-gravitating astrophysical systems can be fully addressed in the Eddington-inspired Born-Infeld gravity. The latter modifies the Jeans instability in high densities environments, while its effects become negligible in star formation regions.

Analysis of Jeans instability from the Boltzmann equation

“…Another method to analyse the Jeans instability is to consider the collisionless Boltzmann equation coupled with the Newtonian Poisson equation (see e.g [5][6][7][8][9][10][11][12]).…”

A kinetic theory of the pulsational mode of gravitational collapse in star-forming molecular clouds

“…The various lines link to md = 2×10 -8 g (red, solid line), md = 3×10 -8 g (blue, dashed line), and md = 4×10 -8 g (black, dotted line), respectively. The different parametric input values for the numerical analysis adopted from reliable astronomical literature [5,6,[16][17][18][19][20][21][22][23] used here are me = 9.1×10 -28 g, mi = 1.67×10 -24 g, ne0 = 1×10 6 cm -3 , ni0 = 5×10 6 cm -3 , ndn0 = 4 cm -3 , ndc0 = 2 cm -3 , Te≃Ti≃1 eV, Td ≃ 2×10 -2 eV, and Zd= 100. It is interestingly seen that the real frequency part (Figs.…”

“…The equations describing the dynamics of the individual constitutive species composing the entire self-gravitating dusty plasma system in the proposed kinetic picture with all the generic astronomical notations [4,18,19,[26][27][28]…”

“…The Jeans instability of a dusty plasma has been extensively studied in the past by several authors in the framework of fluid theory [9][10][11][12][13][14][15][16][17] as well as kinetic theory [4,18,19]. Since the observed degree of ionization (~10 -7 ) in interstellar DMCs is rather low, it is realistic to assume the presence of charged and neutral dust grains along with plasma particles in a molecular cloud.…”

Jeans analysis in energy–momentum-squared gravity

“…Since such a scale is strongly dependent by the underlying theory of gravity, it has been used to probe several modified theories of gravity [47,48,49,50]. Besides the stability criteria for spherically symmetric perturbations, [51] investigated the stability condition of all local axisymmetric perturbations introducing the dimensionless parameter Q = csκ πGΣ , where κ is the epicyclic frequency and Σ is the surface density of the system.…”