Scalar field, nonminimal coupling, and cosmology

Journal Article · Fri Nov 15 04:00:00 EST 1991 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.44.3136· OSTI ID:5994435

Demianski, M ^[1]; de Ritis, R; Marmo, G; Platania, G; Rubano, C; Scudellaro, P; Stornaiolo, C ^[2]

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1. Institute for Theoretical Physics, University of Warsaw, Warsaw (Poland) International Center for Relativistic Astrophysics, Dipartimento di Fisica, Universita di Roma La Sapienza,'' Rome (Italy)
2. Dipartimento di Scienze Fisiche (Universita di Napoli) Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Mostra d'Oltremare, pad. 19, 80125 Napoli (Italy)

We study the dynamics of a flat Friedmann-Robertson-Walker universe filled with a self-interacting scalar field nonminimally coupled to the gravitational field. Dynamical equations for the system can be derived from a pointlike Lagrangian. For this system an additional Noether symmetry exists provided that the coupling constant {xi} is equal to 0 or 1/6. When {xi}=1/6 the scalar potential has to be constant. In this case we obtain an exact solution. We also analyze the behavior of the scalar field when {xi}{ne}0, 1/6. Most of the considered solutions are unphysical but there exists a very interesting case in which the effective cosmological constant is rapidly changing, which might lead to inflation.

• OSTI ID: 5994435
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 44:10; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

661310* -- Relativity & Gravitation-- (1992-)
662110 -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CONFORMAL INVARIANCE
COSMOLOGY
COUPLING CONSTANTS
DIFFERENTIAL EQUATIONS
EQUATIONS
FUNCTIONS
GRAVITATIONAL FIELDS
INVARIANCE PRINCIPLES
KLEIN-GORDON EQUATION
LAGRANGIAN FUNCTION
PARTIAL DIFFERENTIAL EQUATIONS
SCALAR FIELDS
SYMMETRY
WAVE EQUATIONS