Testing power-law cosmology with galaxy clusters

Abstract

Power-law cosmologies, in which the cosmological scale factor evolves as a power law in the age, $a \propto t^α$ with $α\ga 1$, regardless of the matter content or cosmological epoch, is comfortably concordant with a host of cosmological observations.} {In this article, we use recent measurements of the X-ray gas mass fractions in clusters of galaxies to constrain the $α$ parameter with curvature $k = \pm1, 0$. We find that the best fit happens for an open scenario with the power index $α= 1.14 \pm 0.05$, though the flat and closed model can not be rule out at very high confidence level.} {Our results are in agreement with other recent analyses and show that the X-ray gas mass fraction measurements in clusters of galaxies provide a complementary test to the power law cosmology.

8 pages, 2 figures, 1 table, accepted for publication in A&A