\gamma vs time I have used an emperical relation of scalar field $\phi=\phi_0(\frac{a}{a_0})^n$ where n is $\frac{-G \ddot}{GH}$ from recent studied n is found negative and present value of $\gamma$ lies between -0.6 and -0.67 which is sufficient for accelerated expansion. Taking this into account I have chosen 3 values of n and plot for $\gamma$ vs t and found the time for which there is transition from +ve pressure to -ve pressure and start up time of accelerated expansion. But for the positive $\gamma$ if we take into account at very early epoch $\gamma=1/3$ and then followed by $\gamma=0$ and then negative and less than -0.3 to accelerated expansion. But here initially the gamma increases with time ,but $\gamma$ has to decrease with time from 1/3 to 0 and then -ve??


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.