Scalar-tensor theory with Lagrange multipliers: a way of understanding the cosmological constant problem, and future singularities

Abstract

The use of Lagrange multipliers in the context of quintessence/phantom scalar fields allows to constrain the behavior of the scalar field, which provides a powerful tool, not only for the reconstruction of cosmological solutions but also for the study of some problems in cosmology and gravitational physics. In the present paper, we focus on the reconstruction of cosmological solutions capable of controlling the cosmological constant value by imposing a constraint on the scalar field, providing a relaxation mechanism of the value of the cosmological constant. The formalism is also extended to the study of phantom scalar fields with a future singularity and their conformal transformation to the Jordan frame, where a type of modified gravity, constrained by the Lagrange multiplier, is obtained.

10 pages. Version accepted in Phys. Rev. D

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Cited by in corpus (17)

• Holographic Dark Energy
• Conservation laws in theories with universal gravity/matter coupling
• Weyl-Cartan-Weitzenböck gravity through Lagrange multiplier
• $f(R)$-gravity from Killing Tensors
• Theoretical and observational constraints of viable f(R) theories of gravity
• Gauss-Bonnet dark energy by Lagrange multipliers
• Renormalization-group inflationary scalar electrodynamics and SU(5) scenarios confronted with Planck2013 and BICEP2 results
• Scalar field cosmology modified by the Generalized Uncertainty Principle
• Exact Solutions in Chiral Cosmology
• Non-minimally coupled dark matter: effective pressure and structure formation
• Dynamics of Chiral Cosmology
• Cosmological evolution, future singularities, Little Rip and Pseudo-Rip in viable f(R) theories and their scalar-tensor counterpart
• Analyzing modified unimodular gravity via Lagrange multipliers
• Observational constraints on a cosmological model with Lagrange multipliers
• Parametrizing the transition to the phantom epoch with Supernovae Ia and Standard Rulers
• Black branes in four-dimensional conformal equivalent theories
• Lagrange Multipliers and Third Order Scalar-Tensor Field Theories