# Disformal couplings and the dark sector of the universe

@article{deBruck2015DisformalCA, title={Disformal couplings and the dark sector of the universe}, author={Carsten van de Bruck and Jack Morrice}, journal={Journal of Cosmology and Astroparticle Physics}, year={2015}, volume={2015}, pages={036 - 036} }

Interactions between dark matter and dark energy, allowing both conformal and and disformal couplings, are studied in detail. We discuss the background evolution, anisotropies in the cosmic microwave background and large scale structures. One of our main findings is that a large conformal coupling is not necessarily disallowed in the presence of a general disformal term. On the other hand, we find that negative disformal couplings very often lead to instabilities in the scalar field. Studying…

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## References

SHOWING 1-10 OF 69 REFERENCES

### Screening modifications of gravity through disformally coupled fields.

- PhysicsPhysical review letters
- 2012

It is shown that extensions to general relativity, which introduce a strongly coupled scalar field, can be viable if the interaction has a nonconformal form and if the field is locally static and smooth, the coupling becomes invisible in the Solar System: this is the disformal screening mechanism.

### Disformal scalar fields and the dark sector of the universe

- Physics
- 2010

Disformal transformations have proven to be very useful to devise models of the dark sector. In the present paper we apply such transformation to a single scalar field theory as a way to drive the…

### Dynamics of dark energy with a coupling to dark matter

- Physics
- 2008

Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling…

### Constraining disformally coupled scalar fields

- Physics
- 2014

Light scalar fields can naturally couple disformally to matter fields. Static, nonrelativistic sources do not generate a classical field profile for a disformally coupled scalar, and so such scalars…

### Constraints on nonconformal couplings from the properties of the cosmic microwave background radiation.

- PhysicsPhysical review letters
- 2013

A disformal coupling of the field to the cosmic microwave background is shown to affect the evolution of the energy density in the radiation fluid and produces a modification of the distribution function of the CMB, which vanishes if photons and baryons couple in the same way to the scalar.

### Modified gravity and the radiation dominated epoch

- Physics
- 2013

In this paper we consider scalar-tensor theories, allowing for both conformal and disformal couplings to a fluid with a general equation of state. We derive the effective coupling for both background…

### DBI Galileons in the Einstein Frame: Local Gravity and Cosmology

- Physics
- 2013

It is shown that a disformally coupled theory in which the gravitational sector has the Einstein-Hilbert form is equivalent to a quartic Dirac-Born-Infeld Galileon Lagrangian, possessing nonlinear…

### Models of dark matter coupled to dark energy

- Physics, Mathematics
- 2013

We present three distinct types of models of dark energy in the form of a scalar field which is explicitly coupled to dark matter. Our construction draws from the pull-back formalism for fluids and…

### Towards viable cosmological models of disformal theories of gravity

- Physics
- 2015

The late-time cosmological dynamics of disformal gravity are investigated using dynamical systems methods. It is shown that in the general case there are no stable attractors that screen fifth-forces…

### Time-dependent couplings in the dark sector: from background evolution to non-linear structure formation

- Physics
- 2010

We present a complete numerical study of cosmological models with a time dependent coupling between the dark energy component driving the present accelerated expansion of the Universe and the Cold…