Search results for "Stellar dynamics"
showing 3 items of 3 documents
Interior spacetimes of stars in Palatinif(R)gravity
2006
We study the interior spacetimes of stars in the Palatini formalism of f(R) gravity and derive a generalized Tolman-Oppenheimer-Volkoff and mass equation for a static, spherically symmetric star. We show that matching the interior solution with the exterior Schwarzschild-De Sitter solution in general gives a relation between the gravitational mass and the density profile of a star, which is different from the one in General Relativity. These modifications become neglible in models for which $\delta F(R) \equiv \partial f/\partial R - 1$ is a decreasing function of R however. As a result, both Solar System constraints and stellar dynamics are perfectly consistent with $f(R) = R - \mu^4/R$.
Computational Approach to Gravitational Waves Forms in Stellar Systems as Complex Structures through Keplerian Parameters
2009
In this paper we investigate the gravitational waves emission by stellar dynamical structures as complex systems in the quadrupole approximation considering bounded and unbounded orbits. Precisely, after deriving analytical expressions for the gravitational wave luminosity, the total energy output and gravitational radiation amplitude, we present a computational approach to evaluate the gravitational wave-forms from elliptical, circular, parabolic and hyperbolic orbits as a function of Keplerian parameters.
Rotational effects on the oscillation frequencies of newly born proto-neutron stars
2003
In this paper we study the effects of rotation on the frequencies of the quasi-normal modes of a proto-neutron star (PNS) born in a gravitational collapse during the first minute of life. Our analysis starts a few tenths of seconds after the PNS formation, when the stellar evolution can be described by a sequence of equilibrium configurations. We use the evolutionary models developed by Pons et al. (1999; 2001) that describe how a non rotating star cools down and contracts while neutrino diffusion and thermalization processes dominate the stellar dynamics. For assigned values of the evolution time, we set the star into slow rotation and integrate the equations of stellar perturbations in th…