Peculiarity of dynamics of scalar field coupled to dark matter
Interacting quintessence model
Given that the quintessence field and the dark matter have unknown physical natures, there seem to be no a priori reasons to exclude a coupling between the two components. Let us consider a two-component system (scalar field $\varphi$ + dark matter) with the energy density and pressure \[\rho=\rho_\varphi+\rho_{dm},\quad p=p_\varphi+p_{dm}\] (we do not exclude the possibility of warm DM ($p_{dm}\ne0$).) If some interaction exists between the scalar field and DM, then \[\dot\rho_{dm}+3H(\rho_{dm}+p_{dm})=Q\] \[\dot\rho_\varphi+3H(\rho_\varphi+p_\varphi)=-Q.\] Using the effective pressures $\Pi_\varphi$ and $\Pi_{dm}$, \[Q=-3H\Pi_{dm}=3H\Pi_\varphi\] one can transit to the system \begin{align} \nonumber \dot\rho_{dm}+3H(\rho_{dm}+p_{dm}+\Pi_{dm}) & =0,\\ \nonumber \dot\rho_\varphi+3H(\rho_\varphi+p_\varphi+\Pi_\varphi) & =0. \end{align}
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
Problem 1
