Quantum mechanics

Theoretical physics

Engineering

Inflation (cosmology)

Cosmology

Redshift

Galaxy

Statistics

Perturbation theory (quantum mechanics)

Correlation function (quantum field theory)

Particle physics

Astrophysics

Cosmological perturbation theory

Constraint (computer-aided design)

Scaling

Statistical physics

Metric expansion of space

Dark energy

Mechanical engineering

Statistic

Physics

Dielectric

Mathematics

Baryon acoustic oscillations

Geometry

General relativity

Journal of Cosmology and Astroparticle Physics

Future large scale structure surveys will provide increasingly tight constraints on our cosmological model. These surveys will report results on the distance scale and growth rate of perturbations through measurements of Baryon Acoustic Oscillations and Redshift-Space Distortions. It is interesting to ask: what further analyses should become routine, so as to test as-yet-unknown models of cosmic acceleration? Models which aim to explain the accelerated expansion rate of the Universe by modifications to General Relativity often invoke screening mechanisms which can imprint a non-standard density dependence on their predictions. This suggests density-dependent clustering as a `generic' constraint. This paper argues that a density-marked correlation function provides a density-dependent statistic which is easy to compute and report and requires minimal additional infrastructure beyond what is routinely available to such survey analyses. We give one realization of this idea and study it using low order perturbation theory. We encourage groups developing modified gravity theories to see whether such statistics provide discriminatory power for their models.

A marked correlation function for constraining modified gravity models