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arXiv · 1711.10793

A Two-point Diagnostic for the HII Galaxy Hubble Diagram

Kyle Leaf·Fulvio Melia
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Abstract

A previous analysis of starburst-dominated HII Galaxies and HII regions has demonstrated a statistically significant preference for the Friedmann-Robertson-Walker cosmology with zero active mass, known as the R_h=ct universe, over LCDM and its related dark-matter parametrizations. In this paper, we employ a 2-point diagnostic with these data to present a complementary statistical comparison of R_h=ct with Planck LCDM. Our 2-point diagnostic compares---in a pairwise fashion---the difference between the distance modulus measured at two redshifts with that predicted by each cosmology. Our results support the conclusion drawn by a previous comparative analysis demonstrating that R_h=ct is statistically preferred over Planck LCDM. But we also find that the reported errors in the HII measurements may not be purely Gaussian, perhaps due to a partial contamination by non-Gaussian systematic effects. The use of HII Galaxies and HII regions as standard candles may be improved even further with a better handling of the systematics in these sources.

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Kyle Leaf, Fulvio Melia. 2017-11-29. A Two-point Diagnostic for the HII Galaxy Hubble Diagram. https://doi.org/10.1093/mnras%2Fstx3109

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