Testing ΛCDM at the lowest redshifts with SN Ia and galaxy velocities

By D. Huterer, D. Shafer, D. Scolnic, F. Schmidt. 2016

146 citations recorded by the source corpus.

Peculiar velocities of objects in the nearby universe are correlated due to the gravitational pull of large-scale structure. By measuring these velocities, we have a unique opportunity to test the cosmological model at the lowest redshifts. We perform this test, using current data to constrain the amplitude of the ``signal'' covariance matrix describing the velocities and their correlations. We consider a new, well-calibrated ``Supercal'' set of low-redshift SNe Ia as well as a set of distances derived from the fundamental plane relation of 6dFGS galaxies. Analyzing the SN and galaxy data separately, both results are consistent with the peculiar velocity signal of our fiducial ΛCDM model, ruling out the noise-only model with zero peculiar velocities at greater than 7σ (SNe) and 8σ (galaxies). When the two data sets are combined appropriately, the precision of the test increases slightly, resulting in a constraint on the signal amplitude of A = 1.05−0.21+0.25, where A = 1 corresponds to our fiducial model. Equivalently, we report an 11% measurement of the product of the growth rate and amplitude of mass fluctuations evaluated at zeff = 0.02, f σ8 = 0.428−0.045+0.048, valid for our fiducial ΛCDM model. We explore the robustness of the results to a number of conceivable variations in the analysis and find that individual variations shift the preferred signal amplitude by less than ∼0.5σ. We briefly discuss our Supercal SN Ia results in comparison with our previous results using the JLA compilation.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/c4979a8cfa3c6825ef37ea6c53e9b469fbc0908c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. A. Riess
2. A. Filippenko
3. R. Kirshner
4. S. Jha
5. D. Scolnic
6. R. Foley
7. R. Kessler
8. Armin Rest

In Instrumentation

1. A. Riess
2. S. Jha
3. R. Kirshner
4. A. Filippenko
5. R. Foley
6. D. Scolnic
7. L. Perivolaropoulos
8. Joe Zuntz

Citations in the corpus

• The Pantheon+ Analysis: Cosmological Constraints (2022, methodology): “Large compilations of low-z SNe Ia enable precision measurements of the local growth-of-structure, typically parameterized by fσ8 (e.g., Huterer et al. 2017; Stahl et al. 2021).”
• Tension and constraints on modified gravity parametrizations of $G_{\textrm{eff}}(z)$ from growth rate and Planck data (2017, background): “[72] Dragan Huterer, Daniel Shafer, Daniel Scolnic, and Fabian Schmidt, “Testing LCDM at the lowest redshifts with SN Ia and galaxy velocities,” (2016), arXiv:1611.”