272 research outputs found
Search for sterile neutrinos in holographic dark energy cosmology: Reconciling Planck observation with the local measurement of the Hubble constant
We search for sterile neutrinos in the holographic dark energy cosmology by
using the latest observational data. To perform the analysis, we employ the
current cosmological observations, including the cosmic microwave background
temperature power spectrum data from the Planck mission, the baryon acoustic
oscillation measurements, the type Ia supernova data, the redshift space
distortion measurements, the shear data of weak lensing observation, the Planck
lensing measurement, and the latest direct measurement of as well. We
show that, compared to the CDM cosmology, the holographic dark energy
cosmology with sterile neutrinos can relieve the tension between the Planck
observation and the direct measurement of much better. Once we include
the measurement in the global fit, we find that the hint of the existence
of sterile neutrinos in the holographic dark energy cosmology can be given.
Under the constraint of the all-data combination, we obtain and , indicating
that the detection of in the holographic dark energy
cosmology is at the level and the massless or very light sterile
neutrino is favored by the current observations.Comment: 10 pages, 4 figures; typos corrected, published in PR
Prospects for Constraining interacting dark energy cosmology with gravitational-wave bright sirens detected by future SKA-era pulsar timing arrays
Pulsar timing arrays (PTAs) have the potential to detect Nanohertz
gravitational waves (GWs) that are usually generated by the individual
inspiraling supermassive black hole binaries (SMBHBs) in the galactic centers.
The GW signals as cosmological standard sirens can provide the absolute cosmic
distances, thereby can be used to constrain the cosmological parameters. In
this paper, we analyze the ability of future SKA-era PTAs to detect the
existing SMBHBs candidates assuming the root mean square of timing noise
, and use the simulated PTA data to constrain the
interacting dark energy (IDE) models with energy transfer rate . We find that, the future SKA-era PTAs will play an important role in
constraining the IDE cosmology. Using only the mock PTA data consisting of 100
pulsars, we obtain
and in the ICDM model, which are much better
than the results from the Planck TT, TE, EE+lowE. However, the PTA data cannot
provide a tight constraint on the coupling parameter compared with
Planck, but the data combination of Planck+PTA can provide a rather tight
constraint, i.e., , since the PTA data could break the
parameter degeneracies inherent in CMB. In the ICDM model, we obtain
and from the Planck+PTA data
combination. In addition, we also find that with the increase of the number of
pulsars in PTA, the constraint results from the Planck+PTA will be further
improved to some extent. We show that the observations of Nanohertz GWs with
future SKA-era PTAs will provide a powerful tool for exploring the nature of
dark energy and measuring the coupling between dark energy and dark matter
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