Figure 2
From: Dynamical system analysis of FLRW models with Modified Chaplygin gas
State space for \(\alpha =1\) and \(\gamma <\frac{2}{3}\). Here, dots denote the solutions of the system; F, M, dS, CH and CD represent Flat FL solution\((\Omega =1, \Omega _\Lambda =0, \Omega _A=0, k=0)\), Milne solution\((\Omega =0, \Omega _\Lambda =0, \Omega _A=0, k=-1)\), de Sitter solution\((\Omega =0, \Omega _\Lambda =1, \Omega _A=0, k=0)\), Chaplygin Gas solution\((\Omega =1,\Omega _\Lambda =0,\Omega _A=\root \alpha + 1 \of {\gamma }, k=0\)) and Chaplygin-de Sitter solution line \((\Omega =\Omega ,\Omega _\Lambda =1-\Omega ,\Omega _A=\root \alpha + 1 \of {\gamma }\Omega ,k=0)\), respectively. z axis corresponds to \(\Omega _A\) for all of the state space. On \(k=+1\) region (middle) vertical and horizontal axes correspond to \(\Omega\) and Q, respectively. On \(k=-1\) region (triangular parts on both sides), M-F and M-dS lines correspond to \(\Omega\) and \(\Omega _\Lambda\) axes, respectively. The right and left parts of the state space represent expanding and contracting universes, respectively. Subscripts on equilibriums refer to the sign of H there. Lines go from red to black. (MATLAB ver. R2019b).
