# Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors

## Abstract

We present forecasts for the accuracy of determining the parameters of a minimal cosmological model and the total neutrino mass based on combined mock data for a future Euclid-like galaxy survey and Planck. We consider two different galaxy surveys: a spectroscopic redshift survey and a cosmic shear survey. We make use of the Monte Carlo Markov Chains (MCMC) technique and assume two sets of theoretical errors. The first error is meant to account for uncertainties in the modelling of the effect of neutrinos on the non-linear galaxy power spectrum and we assume this error to be fully correlated in Fourier space. The second error is meant to parametrize the overall residual uncertainties in modelling the non-linear galaxy power spectrum at small scales, and is conservatively assumed to be uncorrelated and to increase with the ratio of a given scale to the scale of non-linearity. It hence increases with wavenumber and decreases with redshift. With these two assumptions for the errors and assuming further conservatively that the uncorrelated error rises above 2% at k = 0.4 h/Mpc and z = 0.5, we find that a future Euclid-like cosmic shear/galaxy survey achieves a 1-σ error on M{sub ν} close to 32 meV/25more »

- Authors:

- Institut de Théorie des Phénomènes Physiques, École PolytechniqueFédérale de Lausanne, CH-1015, Lausanne (Switzerland)
- Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ, 08540 (United States)
- Kavli Institute for Cosmology and Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA (United Kingdom)
- INAF/Osservatorio Astronomico di Trieste, Via Tiepolo 11, 34143, Trieste (Italy)

- Publication Date:

- OSTI Identifier:
- 22279618

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; COSMOLOGICAL MODELS; COSMOLOGY; ENERGY SPECTRA; ERRORS; GALAXIES; MARKOV PROCESS; MEV RANGE; MONTE CARLO METHOD; NEUTRINOS; NONLINEAR PROBLEMS; RED SHIFT; REST MASS; SHEAR; SPACE

### Citation Formats

```
Audren, Benjamin, Lesgourgues, Julien, Bird, Simeon, Haehnelt, Martin G., and Viel, Matteo, E-mail: benjamin.audren@epfl.ch, E-mail: julien.lesgourgues@cern.ch, E-mail: spb@ias.edu, E-mail: haehnelt@ast.cam.ac.uk, E-mail: viel@oats.inaf.it.
```*Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors*. United States: N. p., 2013.
Web. doi:10.1088/1475-7516/2013/01/026.

```
Audren, Benjamin, Lesgourgues, Julien, Bird, Simeon, Haehnelt, Martin G., & Viel, Matteo, E-mail: benjamin.audren@epfl.ch, E-mail: julien.lesgourgues@cern.ch, E-mail: spb@ias.edu, E-mail: haehnelt@ast.cam.ac.uk, E-mail: viel@oats.inaf.it.
```*Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors*. United States. doi:10.1088/1475-7516/2013/01/026.

```
Audren, Benjamin, Lesgourgues, Julien, Bird, Simeon, Haehnelt, Martin G., and Viel, Matteo, E-mail: benjamin.audren@epfl.ch, E-mail: julien.lesgourgues@cern.ch, E-mail: spb@ias.edu, E-mail: haehnelt@ast.cam.ac.uk, E-mail: viel@oats.inaf.it. Tue .
"Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors". United States. doi:10.1088/1475-7516/2013/01/026.
```

```
@article{osti_22279618,
```

title = {Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors},

author = {Audren, Benjamin and Lesgourgues, Julien and Bird, Simeon and Haehnelt, Martin G. and Viel, Matteo, E-mail: benjamin.audren@epfl.ch, E-mail: julien.lesgourgues@cern.ch, E-mail: spb@ias.edu, E-mail: haehnelt@ast.cam.ac.uk, E-mail: viel@oats.inaf.it},

abstractNote = {We present forecasts for the accuracy of determining the parameters of a minimal cosmological model and the total neutrino mass based on combined mock data for a future Euclid-like galaxy survey and Planck. We consider two different galaxy surveys: a spectroscopic redshift survey and a cosmic shear survey. We make use of the Monte Carlo Markov Chains (MCMC) technique and assume two sets of theoretical errors. The first error is meant to account for uncertainties in the modelling of the effect of neutrinos on the non-linear galaxy power spectrum and we assume this error to be fully correlated in Fourier space. The second error is meant to parametrize the overall residual uncertainties in modelling the non-linear galaxy power spectrum at small scales, and is conservatively assumed to be uncorrelated and to increase with the ratio of a given scale to the scale of non-linearity. It hence increases with wavenumber and decreases with redshift. With these two assumptions for the errors and assuming further conservatively that the uncorrelated error rises above 2% at k = 0.4 h/Mpc and z = 0.5, we find that a future Euclid-like cosmic shear/galaxy survey achieves a 1-σ error on M{sub ν} close to 32 meV/25 meV, sufficient for detecting the total neutrino mass with good significance. If the residual uncorrelated errors indeed rises rapidly towards smaller scales in the non-linear regime as we have assumed here then the data on non-linear scales does not increase the sensitivity to the total neutrino mass. Assuming instead a ten times smaller theoretical error with the same scale dependence, the error on the total neutrino mass decreases moderately from σ(M{sub ν}) = 18 meV to 14 meV when mildly non-linear scales with 0.1 h/Mpc < k < 0.6 h/Mpc are included in the analysis of the galaxy survey data.},

doi = {10.1088/1475-7516/2013/01/026},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 01,

volume = 2013,

place = {United States},

year = {Tue Jan 01 00:00:00 EST 2013},

month = {Tue Jan 01 00:00:00 EST 2013}

}