# Measuring the lensing potential with tomographic galaxy number counts

## Abstract

We investigate how the lensing potential can be measured tomographically with future galaxy surveys using their number counts. Such a measurement is an independent test of the standard ΛCDM framework and can be used to discern modified theories of gravity. We perform a Fisher matrix forecast based on galaxy angular-redshift power spectra, assuming specifications consistent with future photometric Euclid-like surveys and spectroscopic SKA-like surveys. For the Euclid-like survey we derive a fitting formula for the magnification bias. Our analysis suggests that the cross correlation between different redshift bins is very sensitive to the lensing potential such that the survey can measure the amplitude of the lensing potential at the same level of precision as other standard ΛCDM cosmological parameters.

- Authors:

- Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, 24 quai Ernest Ansermet, 1211 Genève 4 (Switzerland)

- Publication Date:

- OSTI Identifier:
- 22525208

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Cosmology and Astroparticle Physics

- Additional Journal Information:
- Journal Volume: 2015; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; CORRELATIONS; COSMOLOGICAL CONSTANT; COSMOLOGY; GALAXIES; GRAVITATION; GRAVITATIONAL LENSES; NONLUMINOUS MATTER; PHOTOMETRY; POTENTIALS; RED SHIFT

### Citation Formats

```
Montanari, Francesco, and Durrer, Ruth, E-mail: francesco.montanari@unige.ch, E-mail: ruth.durrer@unige.ch.
```*Measuring the lensing potential with tomographic galaxy number counts*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/10/070.

```
Montanari, Francesco, & Durrer, Ruth, E-mail: francesco.montanari@unige.ch, E-mail: ruth.durrer@unige.ch.
```*Measuring the lensing potential with tomographic galaxy number counts*. United States. doi:10.1088/1475-7516/2015/10/070.

```
Montanari, Francesco, and Durrer, Ruth, E-mail: francesco.montanari@unige.ch, E-mail: ruth.durrer@unige.ch. Thu .
"Measuring the lensing potential with tomographic galaxy number counts". United States. doi:10.1088/1475-7516/2015/10/070.
```

```
@article{osti_22525208,
```

title = {Measuring the lensing potential with tomographic galaxy number counts},

author = {Montanari, Francesco and Durrer, Ruth, E-mail: francesco.montanari@unige.ch, E-mail: ruth.durrer@unige.ch},

abstractNote = {We investigate how the lensing potential can be measured tomographically with future galaxy surveys using their number counts. Such a measurement is an independent test of the standard ΛCDM framework and can be used to discern modified theories of gravity. We perform a Fisher matrix forecast based on galaxy angular-redshift power spectra, assuming specifications consistent with future photometric Euclid-like surveys and spectroscopic SKA-like surveys. For the Euclid-like survey we derive a fitting formula for the magnification bias. Our analysis suggests that the cross correlation between different redshift bins is very sensitive to the lensing potential such that the survey can measure the amplitude of the lensing potential at the same level of precision as other standard ΛCDM cosmological parameters.},

doi = {10.1088/1475-7516/2015/10/070},

journal = {Journal of Cosmology and Astroparticle Physics},

issn = {1475-7516},

number = 10,

volume = 2015,

place = {United States},

year = {2015},

month = {10}

}