scholarly journals Forecasting cosmological bias due to local gravitational redshift

2019 ◽  
Vol 28 (12) ◽  
pp. 1950150
Author(s):  
Haoting Xu ◽  
Zhiqi Huang ◽  
Na Zhang ◽  
Yundong Jiang

When photons from distant galaxies and stars pass through our neighboring environment, the wavelengths of the photons would be shifted by our local gravitational potential. This local gravitational redshift effect can potentially have an impact on the measurement of cosmological distance–redshift relation. Using available supernovae data, Wojtak, Davis and Wiis [J. Cosmol. Astropart. Phys. 2015 (2015) 025] found seemingly large biases of cosmological parameters for some extended models (nonflat [Formula: see text]CDM, [Formula: see text]CDM, etc.). Huang [Phys. Rev. D 91 (2015) 121301] pointed out that, however, the biases can be reduced to a negligible level if cosmic microwave background (CMB) data are added to break the strong degeneracy between parameters in the extended models. In this paper, we forecast the cosmological bias due to local gravitational redshifts for a future WFIRST-like supernovae survey. We find that the local gravitational redshift effect remains negligible, provided that CMB data or some future redshift survey data are added to break the degeneracy between parameters.

2005 ◽  
Vol 216 ◽  
pp. 43-50
Author(s):  
J. B. Peterson ◽  
A. K. Romer ◽  
P. L. Gomez ◽  
P. A. R. Ade ◽  
J. J. Bock ◽  
...  

The Arcminute Cosmology Bolometer Array Receiver (Acbar) is a multifrequency millimeter-wave receiver optimized for observations of the Cosmic Microwave Background (CMB) and the Sunyaev-Zel'dovich (SZ) effect in clusters of galaxies. Acbar was installed on the 2.1 m Viper telescope at the South Pole in January 2001 and the results presented here incorporate data through July 2002. The power spectrum of the CMB at 150 GHz over the range ℓ = 150 — 3000 measured by Acbar is presented along with estimates for the values of the cosmological parameters within the context of ΛCDM models. The inclusion of ΩΛ greatly improves the fit to the power spectrum. Three-frequency images of the SZ decrement/increment are also presented for the galaxy cluster 1E0657–67.


2005 ◽  
Vol 216 ◽  
pp. 28-34
Author(s):  
S. L. Bridle ◽  
A. M. Lewis ◽  
J. Weller ◽  
G. Efstathiou

We reconstruct the shape of the primordial power spectrum from the latest cosmic microwave background data, including the new results from the Wilkinson Microwave Anisotropy Probe (WMAP), and large scale structure data from the two degree field galaxy redshift survey (2dFGRS). We discuss two parameterizations taking into account the uncertainties in four cosmological parameters. First we parameterize the initial spectrum by a tilt and a running spectral index, finding marginal evidence for a running spectral index only if the first three WMAP multipoles (ℓ = 2, 3, 4) are included in the analysis. Secondly, to investigate further the low CMB large scale power, we modify the conventional power-law spectrum by introducing a scale above which there is no power. We find a preferred position of the cut at kc ∼ 3 × 10--4 Mpc--1 although kc = 0 (no cut) is not ruled out.


1999 ◽  
Vol 310 (2) ◽  
pp. 565-570 ◽  
Author(s):  
S. L. Bridle ◽  
V. R. Eke ◽  
O. Lahav ◽  
A. N. Lasenby ◽  
M. P. Hobson ◽  
...  

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Jun Li ◽  
Guang-Hai Guo

AbstractWe consider the scalar induced gravitational waves from the cosmic microwave background (CMB) observations and the gravitational wave observations. In the $$\Lambda $$ Λ CDM+r model, we constrain the cosmological parameters within the evolution of the scalar induced gravitational waves by the additional scalar power spectrum. The two special cases called narrow power spectrum and wide power spectrum have influence on the cosmological parameters, especially the combinations of Planck18+BAO+BK15+LISA. We also compare these numerical results from four datasets within LIGO, LISA, IPTA and FAST projects, respectively. The constraints from FAST have a significant impact on tensor-to-scalar ratio. Besides, we only consider the relic density of induced gravitational waves with respect to different frequencies from CMB scale to high frequencies including the range of LIGO and LISA.


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