Measuring the Expansion or Contraction of Galaxies

Abraham Loeb

Published 2022-02-02Version 1

Galaxies lose mass as a result of their luminosity or gaseous outflows. I calculate the resulting radial migration of stars outwards and show that it could potentially be measured with high resolution spectrographs on the next generation of large telescopes. Substantial accretion of matter in dense cosmic environments could trigger inward stellar migration that would be even more easily measurable.