# Quintessential inflation with α-attractors

## Abstract

A novel approach to quintessential inflation model building is studied, within the framework of α-attractors, motivated by supergravity theories. Inflationary observables are in excellent agreement with the latest CMB observations, while quintessence explains the dark energy observations without any fine-tuning. The model is kept intentionally minimal, avoiding the introduction of many degrees of freedom, couplings and mass scales. In stark contrast to ΛCDM, for natural values of the parameters, the model attains transient accelerated expansion, which avoids the future horizon problem, while it maintains the field displacement mildly sub-Planckian such that the flatness of the quintessential tail is not lifted by radiative corrections and violations of the equivalence principle (fifth force) are under control. In particular, the required value of the cosmological constant is near the eletroweak scale. Attention is paid to the reheating of the Universe, which avoids gravitino overproduction and respects nucleosynthesis constraints. Kination is treated in a model independent way. A spike in gravitational waves, due to kination, is found not to disturb nucleosynthesis as well.

- Authors:

- Consortium for Fundamental Physics, Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)

- Publication Date:

- OSTI Identifier:
- 22676158

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATTRACTORS; COMPUTERIZED SIMULATION; COSMOLOGICAL CONSTANT; COUPLING; DEGREES OF FREEDOM; EQUIVALENCE PRINCIPLE; EXPANSION; GRAVITATIONAL WAVES; GRAVITINOS; MASS; NONLUMINOUS MATTER; NUCLEOSYNTHESIS; RADIATIVE CORRECTIONS; RELICT RADIATION; SUPERGRAVITY; TRANSIENTS; UNIVERSE

### Citation Formats

```
Dimopoulos, Konstantinos, and Owen, Charlotte, E-mail: k.dimopoulos1@lancaster.ac.uk, E-mail: c.owen@lancaster.ac.uk.
```*Quintessential inflation with α-attractors*. United States: N. p., 2017.
Web. doi:10.1088/1475-7516/2017/06/027.

```
Dimopoulos, Konstantinos, & Owen, Charlotte, E-mail: k.dimopoulos1@lancaster.ac.uk, E-mail: c.owen@lancaster.ac.uk.
```*Quintessential inflation with α-attractors*. United States. doi:10.1088/1475-7516/2017/06/027.

```
Dimopoulos, Konstantinos, and Owen, Charlotte, E-mail: k.dimopoulos1@lancaster.ac.uk, E-mail: c.owen@lancaster.ac.uk. Thu .
"Quintessential inflation with α-attractors". United States.
doi:10.1088/1475-7516/2017/06/027.
```

```
@article{osti_22676158,
```

title = {Quintessential inflation with α-attractors},

author = {Dimopoulos, Konstantinos and Owen, Charlotte, E-mail: k.dimopoulos1@lancaster.ac.uk, E-mail: c.owen@lancaster.ac.uk},

abstractNote = {A novel approach to quintessential inflation model building is studied, within the framework of α-attractors, motivated by supergravity theories. Inflationary observables are in excellent agreement with the latest CMB observations, while quintessence explains the dark energy observations without any fine-tuning. The model is kept intentionally minimal, avoiding the introduction of many degrees of freedom, couplings and mass scales. In stark contrast to ΛCDM, for natural values of the parameters, the model attains transient accelerated expansion, which avoids the future horizon problem, while it maintains the field displacement mildly sub-Planckian such that the flatness of the quintessential tail is not lifted by radiative corrections and violations of the equivalence principle (fifth force) are under control. In particular, the required value of the cosmological constant is near the eletroweak scale. Attention is paid to the reheating of the Universe, which avoids gravitino overproduction and respects nucleosynthesis constraints. Kination is treated in a model independent way. A spike in gravitational waves, due to kination, is found not to disturb nucleosynthesis as well.},

doi = {10.1088/1475-7516/2017/06/027},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 06,

volume = 2017,

place = {United States},

year = {Thu Jun 01 00:00:00 EDT 2017},

month = {Thu Jun 01 00:00:00 EDT 2017}

}