Recent content by johnnnyboy92

ohhhh, I see now. Correct me if my interpretation of your answers is wrong, but for cosmology, the mathematical relation between pressure and energy density, where we deal with dilute gases, is the equation of state is P=wε. And, since we are dealing with general relativity, like you guys said...

The acceleration equation is: \frac{\ddot{a}}{a} = -\frac{4πG}{3c^2}(ε+3P) According to this equation, if we have a positive pressure, then the expansion of the universe will slow down. I'm confuse about this because I think of positive pressure resulting from the random thermal motions...

Suppose the energy density of the cosmological constant is equal to the present critical density ε\Lambda = εc,0 = 5200 MeV m-3. What is the total energy of the cosmological constant within a sphere 1 AU in radius? My answer: ε\Lambda = ET / V ET = ε\Lambda * V = (8.33 * 10-10...

How can we use stellar kinematics to measure masses of stars? Any equations or reference papers to explain would be great!