Work

Inflationary twin models

Year: 2020

Type: article

Abstract: We introduce the concept of inflationary twin models, that is, a class of generalized (kinetic or ``K inflation'') field theories which lead exactly to the same cosmological evolution during the inflationary period as a given standard scalar field theory of inflation. The twin concept permits us to introduce generalized, K-inflation theories in a controlled manner, maintaining some inflationary predictions unaltered. Further, this concept allows us to extend analytical tools like the slow-roll expansion to the realm of K-inflation theories, facilitating their investigation. Twins of a standard scalar field model of inflation still may result in different results for some inflationary observables, because of their nontrivial scalar speed of sound. This implies that nonstandard twins may lead to completely viable models of inflation, even if their standard twin is ruled out by observations. We provide some explicit examples of this possibility, including the physical case of a dilaton--Dirac-Born-Infeld theory.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.101.063514

Authors: C. Adam, D. Varela

Institution: Universidade de Santiago de Compostela

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Ministerio de Educación, Cultura y Deporte, Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia, European Regional Development Fund

Awards: G2105991930, G3197532054