TY - JOUR
T1 - Affine equation of state from quintessence and k-essence fields
AU - Quercellini, Claudia
AU - Bruni, Marco
AU - Balbi, Amedeo
PY - 2007
Y1 - 2007
N2 - We explore the possibility that a scalar field with appropriate Lagrangian can mimic a perfect fluid with an affine barotropic equation of state. The latter can be thought of as a generic cosmological dark component evolving as an effective cosmological constant plus a generalized dark matter. As such, it can be used as a simple, phenomenological model for either dark energy or unified dark matter. Furthermore, it can approximate (up to first order in the energy density) any barotropic dark fluid with arbitrary equation of state. We find that two kinds of Lagrangians for the scalar field can reproduce the desired behaviour: a quintessence-like with a hyperbolic potential, or a purely kinetic k-essence one. We discuss the behaviour of these two classes of models from the point of view of the cosmological background, and give some hints on their possible clustering properties
AB - We explore the possibility that a scalar field with appropriate Lagrangian can mimic a perfect fluid with an affine barotropic equation of state. The latter can be thought of as a generic cosmological dark component evolving as an effective cosmological constant plus a generalized dark matter. As such, it can be used as a simple, phenomenological model for either dark energy or unified dark matter. Furthermore, it can approximate (up to first order in the energy density) any barotropic dark fluid with arbitrary equation of state. We find that two kinds of Lagrangians for the scalar field can reproduce the desired behaviour: a quintessence-like with a hyperbolic potential, or a purely kinetic k-essence one. We discuss the behaviour of these two classes of models from the point of view of the cosmological background, and give some hints on their possible clustering properties
U2 - 10.1088/0264-9381/24/22/006
DO - 10.1088/0264-9381/24/22/006
M3 - Article
SN - 0264-9381
VL - 24
SP - 5413
EP - 5425
JO - Classical and Quantum Gravity
JF - Classical and Quantum Gravity
IS - 22
ER -