On the Existence of an Universal Spin-down Equation for Pulsars

Abstract

AbstractThe Taylor expansion of the generalized spin-down equation= −f(v), derives into the multipolar equation= −gv5–rv3−sv), which is used here to study pulsar evolution. The coefficientsg,rand s can be physically associated to gravitational radiation, magnetic dipolar radiation and particle aceleration. The multipolar expansion with constant coefficients cannot describe theP Ṗdiagram in a consistent manner and therefore it is unlikely a generalized equation of the form= −f(v;t) can be used to describe pulsar evolution. A more general form,= −f(v;t) can be investigated giving to the coefficientsg,rand s time dependence. We consider some explicit functional forms forg(t),r(t) ands(t) which are consistent with observational and theoretical constraints.