2,578 research outputs found
Constraining the dark matter-vacuum energy interaction using the EDGES 21-cm absorption signal
The recent measurement of the global 21-cm absorption signal reported by the
Experiment to Detect the Global Epoch of Reionization Signature (EDGES)
Collaboration is in tension with the prediction of the CDM model at a
significance level. In this work, we report that this tension can
be released by introducing an interaction between dark matter and vacuum
energy. We perform a model parameter estimation using a combined dataset
including EDGES and other recent cosmological observations, and find that the
EDGES measurement can marginally improve the constraint on parameters that
quantify the interacting vacuum, and that the combined dataset favours the
CDM at 68\% CL. This proof-of-the-concept study demonstrates the
potential power of future 21-cm experiments to constrain the interacting dark
energy models.Comment: 6 pages, 5 figures, 1 table; accepted for publication in Ap
A measurement of the Hubble constant using galaxy redshift surveys
We perform a measurement of the Hubble constant, , using the latest
baryonic acoustic oscillations (BAO) measurements from galaxy surveys of 6dFGS,
SDSS DR7 Main Galaxy Sample, BOSS DR12 sample, and eBOSS DR14 quasar sample, in
the framework of a flat CDM model. Based on the Kullback-Leibler (KL)
divergence, we examine the consistency of values derived from various
data sets. We find that our measurement is consistent with that derived from
Planck and with the local measurement of using the Cepheids and type Ia
supernovae. We perform forecasts on from future BAO measurements, and
find that the uncertainty of determined by future BAO data alone,
including complete eBOSS, DESI and Euclid-like, is comparable with that from
local measurements.Comment: 5 pages, 2 figures, 2 tables; accepted for publication in Ap
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