AST 341 Lecture Notes - Lecture 16: Degenerate Matter, Electron Rest Mass, Particle Velocity
25 Dec 2016
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Document Summary
Before discussing the end states of stars, we need to make a digression on the topic of degeneracy pressure, since this plays a fundamental role for white dwarfs and neutron stars. It becomes particularly important for high densities and/or very low temperatures. Let"s start by considering the familiar case of an ordinary, classical gas. Since the momentum is given by ~p = m~v, if we plot the momenta of particles in a 3d space of px, py, and pz, then as t decreases the particles become concentrated near the origin. At low enough temperatures/high enough densities, the concentration of particles with similar (low) values of their momenta would then violate a fundamental principle of quantum mechanics: the pauli exclusion principle. This states that no two electrons can occupy the same quantum state, i. e. have the same location, momentum and spin. Particles which do not obey the pauli exclusion principle are called bosons (they have integer spins).
