- #1
alejandrito29
- 150
- 0
I am read the pag 190 of Dodelson bock, where use the following relation
[tex] \rho_{DM}= \rho \frac{y}{y+1} [/tex]. where [tex] y= a/a_{eq}=\rho_{DM}/\rho_{rad}[/tex]
i tried using the tipically relation [tex] \rho = \rho_{rad} a^-4+ \rho_{DM} [/tex]
but, i don't understand,
healp please
[tex] \rho_{DM}= \rho \frac{y}{y+1} [/tex]. where [tex] y= a/a_{eq}=\rho_{DM}/\rho_{rad}[/tex]
i tried using the tipically relation [tex] \rho = \rho_{rad} a^-4+ \rho_{DM} [/tex]
but, i don't understand,
healp please