Open AccessStability of polar oscillations of non‐rotating Newtonian superfluid stars
Author(s) -
Wong K. S.
Publication year - 2009
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2009.14706.x
Subject(s) - physics , polar , superfluidity , instability , positive definiteness , newtonian fluid , stability (learning theory) , classical mechanics , astrophysics , mechanics , positive definite matrix , condensed matter physics , quantum mechanics , eigenvalues and eigenvectors , machine learning , computer science
In this paper, we shall study the problem of stability of polar oscillations of a non‐rotating Newtonian superfluid star. We find that the stability of the latter system is guaranteed by the positive definiteness of a matrix quantity. We also find conditions which characterize the occurrence of zero‐frequency polar modes, which marks the onset of polar instability. We find that the negative definiteness of the mentioned matrix quantity implies instability of the system. We apply our results to show that the polar oscillations of a non‐rotating Newtonian superfluid star in the zero‐temperature approximation are marginally stable.