Testing theories in barred spiral galaxies
  According to one version of the recently proposed "manifold" theory that
explains the origin of spirals and rings in relation to chaotic orbits,
galaxies with stronger bars should have a higher spiral arms pitch angle when
compared to galaxies with weaker bars. A sub-sample of barred-spiral galaxies
in the Ohio State University Bright Galaxy Survey, was used to analyze the
spiral arms pitch angle. These were compared with bar strengths taken from the
literature. It was found that the galaxies in which the spiral arms maintain a
logarithmic shape for more than 70$\degr$ seem to corroborate the predicted
trend.
