Non-adiabatic stellar pulsation.

8 - Stellar Pulsation and Oscillation

That some stars vary in brightness has been known from time immemorial. That this variation is the result of intrinsic changes in the star itself has been known for less than 100 years and the causes of those variations have been understood for less than 30 years. It is not a simple matter to distinguish the light variations resulting from eclipses by a companion from those caused by physical c...

Adiabatic Invariants in Stellar Dynamics: I. Basic Concepts

The adiabatic criterion, widely used in astronomical dynamics, is based on the harmonic oscillator. It asserts that the change in action under a slowly varying perturbation is exponentially small. Recent mathematical results precisely deene the conditions for invariance show that this model does not apply in general. In particular, a slowly varying perturbation may cause signiicant evolution st...

Adiabatic Invariants in Stellar Dynamics .1. Basic Concepts

Electronic non-adiabatic states

A novel treatment of non-adiabatic couplings is proposed. The derivation starts from the long-known, but not well-known, fact that the wave function of the complete system of elctrons and nuclei can be written, without approximation, as a Born-Oppenheimer-type product of a nuclear wavefunction, X(R), and an electronic one, ΦR(r), which depends parametrically on the nuclear configuration R. From...

Adiabatic Invariants in Stellar Dynamics .2. Gravitational Shocking