Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism

Details Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism

Jun 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994a%26a...286..879v&link_type=abstract

Astronomy and Astrophysics 286, 879-889 (1994)

Astronomy and Astrophysics

Astrophysics

11

Stars: Variable, Stars: Oscillations Of, Methods: Analytical

Scientific paper

A Hamiltonian formalism for the study of nonlinear, nonradial, isentropic oscillations of a spherically symmetric and static equilibrium star is presented. The Hamiltonian is defined as the sum of the Lagrangian perturbations of the kinetic, internal, and gravitational potential energies of the star and is constructed up to the fourth order in the components of the Lagrangian displacement. From the Hamiltonian equations, a second-order differential equation for the amplitude of a linear, isentropic mode is derived that is of the third order in the amplitudes of the linear, isentropic modes. This equation is identical with the coupled-mode equation for nonradial, isentropic oscillations that can be derived from the equation of motion. The linear, isentropic modes are coupled through coupling coefficients appearing in the nonlinear terms of the coupled-mode equations. From the Hamiltonian formalism, it follows naturally that these coupling coefficients are symmetric in the linear, isentropic eigenfunctions involved. The coupling coefficients are determined for low-order modes of a polytropic model with index equal to three. For modes with equal radial displacement at the surface of the model, it is seen that modes couple most strongly with modes with nearly the same radial orders. Also, higher-order modes are more influenced by the nonlinearities than lower-order modes. The coupling coefficients are mainly determined by the contributions from the outer regions of the model.

Affiliated with

Also associated with

No associations

Rating

Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear, nonradial, isentropic oscillations of stars: Hamiltonian formalism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1862203