Recent content by addaF

For simplicity I'm thinking to an unidimensional gas with a temperature ##T##. For what we said i expect that, on average, the particles moves at ##v = \sqrt{2 kT /M}## which is also called thermal velocity. But from equipartition theorem, since i have only one dimension, i also expect that the...

I just recall the two expression for the Maxwell-Boltzmann distribution: $$ P(v)dv = \left( \dfrac{m}{2 \pi k T} \right)^{3/2} 4 \pi v^2 \exp \left(- \dfrac{mv^2}{kT} \right) dv \qquad P(E)dE = \left( \dfrac{4E}{\pi} \right)^{1/2} \dfrac{e^{-E/kT}}{\left( kT \right)^{3/2}} dE$$ The left...

Hi, Precisely ## k ## refers to the spatial curvature of our Universe. Actually ## k \neq 0 ## but It is really close to ##0##. $$ \begin{cases} k > 0 \quad \text{closed "spherical" universe} \\ k = 0 \quad \text{flat universe} \\ k < 0 \quad \text{open "hyperbolic" universe} \end{cases} $$ The...

Yes, of course I forgot the mass in the 4-momentum definition. I immediately realized it as soon as I read your suggestion. I was writing the 3-momentum modulus like in Minkowski metric. Thank you very much for the reply.

I'm happy to join the community! I'm from Italy and I have a Bachelor degree in Physics. I'm currently attending a Master degree in Physics of the Universe. I'm more interested in Astrophysics and Cosmology, in which I'm currently developing my knowledge. See you in the forum!

Homework Statement I'd like to calculate the form of Liouville operator in a Robertson Walker metric. Homework Equations The general form is $$ \mathbb{L} = \dfrac{\text{d} x^\mu}{\text{d} \lambda} \dfrac{\partial}{\partial x^\mu} - \Gamma^{\mu}_{\nu \rho} p^{\nu} p^{\rho}...