Genesis of cosmological tracker fields

Abstract

The role of the quintessence field as a probable candidate for the repulsive dark energy, the conditions for tracking and the requisites for tracker fields are examined. The concept of 'integrated tracking' is introduced and a new criterion for the existence of tracker potentials is derived assuming monotonic increase in the scalar energy density parameter Ω φ with the evolution of the universe as suggested by the astrophysical constraints. It provides a technique to investigate generic potentials of the tracker fields. The general properties of the tracker fields are discussed and their behaviour with respect to tracking parameter ǫ is analyzed. It is shown that the tracker fields around the limiting value ǫ ≃ 2 3 give the best fit with the observational constraints.

Genesis of Dark Energy: Dark Energy as Consequence of Release and Two-Stage Tracking of Cosmological Nuclear Energy

“…At Z = 10 10 , x ≈ 0; at Z = 80, x = 0.0003; at Z = 12, x = 0.01; at Z = 3, x = 0.1; at Z = 0.5, x = 0.5 and at Z = 0, x = 0.7. It may be noted that these estimates are quite reasonable and satisfy necessary astrophysical constraints [49]; as shown in Fig. 4, the density ratio x is initially too low and remains low till galaxy formation.…”

“…As shown (Fig. 3) in subsequent section of the paper; this dark energy is produced earlier but released free later, of course quantity-wise ( x = 0.0003) insignificant; remains low during galaxy formation (say, at Z = 3, x = 0.1), becomes 50% at transition (Z = 0.5, x = 0.5) and emerges as dominant at present time (Z = 0, x = 0.7), satisfying all the astrophysical constants [49].…”

“…Though the decay of matter and energy (radiation-energy and dark-energy) could possibly be coupled in complex-ways, but a two-stages tracking of dark-energy as described herein (as follows) explains the past and present scenario in a reasonably good way, as it is in accordance (as shown in Sect. 4) with the astrophysical constraints [49]. Dark energy in fact is the released nuclear binding energy of cosmos.…”

Scalar fields properties for flat galactic rotation curves

“…Unification theories and particularly supersymmetry predict the existence of scalar fields, which thus deserve be taken into account in cosmology. Most of time, only their cosmological consequences are analysed: quintessence phenomenon (Johri 2001;Sahni 2000), isotropisation (Fay 2001) or inflation for instance. However, they could also be present at galactic scale.…”

Dark energy as a manifestation of the non-constant cosmological constant

“…The search for various alternative approaches for dark energy mainly includes the minimally coupled (Ratra and Peebles 1988;Caldwell et al 1998;Johri 2001) or the interacting scalar field quintessence models (Khoury and Weltman 2004;Zimdahl et al 2001) and the cosmological constant (Peebles and Ratra 2003). Some authors have proposed a single scalar field that produces the early-and the late-time inflation (Peebles and Vilenkin 1999), or the thawing and freezing models (Caldwell and Linder 2005).…”