What galaxy surveys really measure

By C. Bonvin, R. Durrer. 2011

373 citations recorded by the source corpus.

In this paper we compute the quantity which is truly measured in a large galaxy survey. We take into account the effects coming from the fact that we actually observe galaxy redshifts and sky positions and not true spatial positions. Our calculations are done within linear perturbation theory for both the metric and the observer velocities but they can be used for non-linear matter power spectra. We shall see that the complications due to the fact that we only observe on our background lightcone and that we do not truly know the distance of the observed galaxy, but only its redshift is not only an additional difficulty, but even more a new opportunity for future galaxy surveys.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/8e6b369c73fd9b71979de9917156c26eaa52aee7

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

In Instrumentation

Citations in the corpus

H i intensity mapping: a single dish approach (2012, background): “…the values in an unperturbed universe, that is, we ignore the effects of peculiar velocities, which will lead to redshift space distortions that could be important on small scales, and the Sachs-Wolfe effects which could be important on large scales (Challinor & Lewis 2011; Bonvin & Durrer 2011).”
Probing primordial non-Gaussianity with SKA galaxy redshift surveys: a fully relativistic analysis (2014, background): “The remaining relativistic contributions are both local and integrated terms (Yoo et al. 2009; Yoo 2010; Bonvin & Durrer 2011; Challinor & Lewis 2011; Jeong et al. 2012; Bertacca et al. 2012), namely δobsg = (b+∆b)δcs− (1 + z) H (ni∂i) 2V −2 (1−Q)κ+δloc+δint.”
Single-field consistency relations of large scale structure part II: resummation and redshift space (2013, background): “ the Newtonian and relativistic eﬀects which relate the correlation functions of the density contrast and the velocity with the actual measurement of the galaxy position and redshift (see for example [7, 8, 9, 10]). The next natural step would be to write consistency relations for the observed quant”
The CLASSgal code for relativistic cosmological large scale structure (2013, methodology): “The result of [11] for the perturbation of number counts in direction n and at redshift z reads:”
Galaxy Bias and non-Linear Structure Formation in General Relativity (2011, result): “[40, 41, 42, 30] appeared which treat problems similar to ours and reach similar conclusions where there is overlap with our study.”
A unified pseudo-Cℓ framework (2018, background): “…as a function of frequency ν and sky position θ̂, angular 2-point correlators play a particularly central role in most cosmological analyses, both in the form of configurationspace two-point correlation functions ξ(θ) and as Fourierspace1 power spectra C` (Asorey et al. 2012; Bonvin & Durrer 2011).”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, background): “Large-scale homogeneity is usually assumed without proof when analyzing certain cosmological probes (Bonvin and Durrer 2011).”