Recent content by darkdark10

Now we have a particle-antiparticle asymmetry problem. But, if we define electron and neutrino as antiparticle, will there be a problem? Original formula Modified formula Original formula Modified formula If the classification of electron and neutrino is changed to antiparticles, the...

Your argument( ) leads to: \rho + \frac{{3P}}{{{c^2}}} = {\rho _{rad}} + \frac{{3(\frac{1}{3}{\rho _{rad}}{c^2})}}{{{c^2}}} = 2{\rho _{rad}} Your argument leads to the claim that when matter and radiation have the same energy density ρ0, the radiation exerts twice the gravitational force than...

We know that mass density = energy density/c^2. The question is, when entering the expression (ρ+3P/c^2), which form is correct? When looking at the radiation term, \rho + \frac{{3P}}{{{c^2}}} = {\rho _{rad}} + \frac{{3(\frac{1}{3}{\rho _{rad}}{c^2})}}{{{c^2}}} = 2{\rho _{rad}} or \rho +...

\frac{1}{R}\frac{{{d^2}R}}{{d{t^2}}} = - \frac{{4\pi G}}{3}\left[ {{\rho _m} + {\rho _{rad}} + {\rho _\Lambda } + \frac{{3({P_m} + {P_{rad}} + {P_\Lambda })}}{{{c^2}}}} \right] In the Friedmann equation, ρ is the mass density. === https://en.wikipedia.org/wiki/Friedmann_equations They were...

In the book(An Introduction to Modern Astrophysics - Bradley W. Carroll and Dale A.Ostile) Pressure P = equivalent energy density of kinetic energy P/c^2 = equivalent mass density of kinetic energy Isn't the pressure P in the acceleration equation the equivalent energy density of kinetic energy?

Currently, dark energy is described as a being that exerts a negative pressure while having a positive energy density. {\rho _\Lambda } + 3{P_\Lambda } = {\rho _\Lambda } + 3( - {\rho _\Lambda }) = - 2{\rho _\Lambda } However, there seems to be a problem with the negative pressure assertion...