# Reconstruction of interacting dark energy models from parametrizations

## Abstract

Models with interacting dark energy can alleviate the cosmic coincidence problem by allowing dark matter and dark energy to evolve in a similar fashion. At a fundamental level, these models are specified by choosing a functional form for the scalar potential and for the interaction term. However, in order to compare to observational data it is usually more convenient to use parametrizations of the dark energy equation of state and the evolution of the dark matter energy density. Once the relevant parameters are fitted, it is important to obtain the shape of the fundamental functions. In this paper I show how to reconstruct the scalar potential and the scalar interaction with dark matter from general parametrizations. I give a few examples and show that it is possible for the effective equation of state for the scalar field to cross the phantom barrier when interactions are allowed. I analyze the uncertainties in the reconstructed potential arising from foreseen errors in the estimation of fit parameters and point out that a Yukawa-like linear interaction results from a simple parametrization of the coupling.

- Authors:

- Instituto de Fisica Teorica - UNESP Rua Pamplona, 145, 01405-900, Sao Paulo, SP (Brazil)

- Publication Date:

- OSTI Identifier:
- 21020351

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.75.083509; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BASIC INTERACTIONS; COMPARATIVE EVALUATIONS; COSMOLOGY; COUPLING; ENERGY DENSITY; EQUATIONS OF STATE; NONLUMINOUS MATTER; PHANTOMS; POTENTIALS; SCALAR FIELDS

### Citation Formats

```
Rosenfeld, R.
```*Reconstruction of interacting dark energy models from parametrizations*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.083509.

```
Rosenfeld, R.
```*Reconstruction of interacting dark energy models from parametrizations*. United States. doi:10.1103/PHYSREVD.75.083509.

```
Rosenfeld, R. Sun .
"Reconstruction of interacting dark energy models from parametrizations". United States.
doi:10.1103/PHYSREVD.75.083509.
```

```
@article{osti_21020351,
```

title = {Reconstruction of interacting dark energy models from parametrizations},

author = {Rosenfeld, R.},

abstractNote = {Models with interacting dark energy can alleviate the cosmic coincidence problem by allowing dark matter and dark energy to evolve in a similar fashion. At a fundamental level, these models are specified by choosing a functional form for the scalar potential and for the interaction term. However, in order to compare to observational data it is usually more convenient to use parametrizations of the dark energy equation of state and the evolution of the dark matter energy density. Once the relevant parameters are fitted, it is important to obtain the shape of the fundamental functions. In this paper I show how to reconstruct the scalar potential and the scalar interaction with dark matter from general parametrizations. I give a few examples and show that it is possible for the effective equation of state for the scalar field to cross the phantom barrier when interactions are allowed. I analyze the uncertainties in the reconstructed potential arising from foreseen errors in the estimation of fit parameters and point out that a Yukawa-like linear interaction results from a simple parametrization of the coupling.},

doi = {10.1103/PHYSREVD.75.083509},

journal = {Physical Review. D, Particles Fields},

number = 8,

volume = 75,

place = {United States},

year = {Sun Apr 15 00:00:00 EDT 2007},

month = {Sun Apr 15 00:00:00 EDT 2007}

}