FLRW cosmology with EDSFD parametrization
J. K. Singh, Ritika Nagpal
Abstract
Abstract In this paper, we study a cosmological model in the background of Friedmann–Lemaitre–Robertson–Walker (FLRW) space time by assuming an appropriate parametrization in the form of a differential equation in terms of energy density of scalar field $$\rho _{\phi } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>ρ</mml:mi><mml:mi>ϕ</mml:mi></mml:msub></mml:math> , which is defined as Energy Density Scalar Field Differential equation (EDSFD) parametrization. The EDSFD parametrization leads to a required phase transition from early deceleration to present cosmic acceleration. This parametrization is used to reconstruct the equation of state parameter $$ \omega _{\phi }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>ω</mml:mi><mml:mi>ϕ</mml:mi></mml:msub></mml:math> in terms of redshift z i.e. $$ \omega _{\phi }(z) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>ω</mml:mi><mml:mi>ϕ</mml:mi></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>z</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math> to examine the evolutionary history of the universe in a flat FLRW space time. Here, we constrain the model parameter using the various observational datasets of Hubble parameter H ( z ) , latest Union 2.1 compilation dataset SNeIa , BAO , joint dataset $$H(z)+SNeIa $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>H</mml:mi><mml:mo>(</mml:mo><mml:mi>z</mml:mi><mml:mo>)</mml:mo><mml:mo>+</mml:mo><mml:mi>S</mml:mi><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>I</mml:mi><mml:mi>a</mml:mi></mml:mrow></mml:math> and $$ H(z)+SNeIa+BAO $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>H</mml:mi><mml:mo>(</mml:mo><mml:mi>z</mml:mi><mml:mo>)</mml:mo><mml:mo>+</mml:mo><mml:mi>S</mml:mi><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>I</mml:mi><mml:mi>a</mml:mi><mml:mo>+</mml:mo><mml:mi>B</mml:mi><mml:mi>A</mml:mi><mml:mi>O</mml:mi></mml:mrow></mml:math> for detail analysis of the behavior of physical parameters and we find its best fit present value. Also, we discuss the dynamics of reheating phase after inflation, analyse the behaviors of the physical features using some diagnostic tools, and examine the viability of our parametric model.