Using the conventions of http://www.damtp.cam.ac.uk/user/db275/Cosmology/Chapter4.pdf (not mine).
For a flat FRW perturbed universe, the metric is can be written in general as:
ds^2=a^2(\tau)[(1+2A)dt^2-B_idtdx^i-(\delta_{ij}+h_{ij})dx^idx^j]
I understand intuitively that we can decompose Bi...
Well, the idea is that the Hamiltonian is given by \mathcal{H}=\Sigma_i \pi_i \dot{\phi} - \mathcal{L}, and when we include interactions between \phi and A_\mu we get that it is the sum between the free K.G. Lagrangian, the free Maxwell Lagrangian, and the interaction Lagrangian I gave above...
Homework Statement
Problem 7.15 from Aitchison and Hey, Volume I, 3rd Edition. Verify the forum (7.139) of the interaction Hamiltonian \mathcal{H_{S}^{'}}, in charged spin-0 electrodynamics.
Equation 7.139 is
\mathcal{H_{S}^{'}}= - \mathcal{L}_{int} - q^2 (A^0)^2 \phi^{\dagger} \phi...
I am planning on working through Dodelson's cosmology book, but I find my knowledge of things like Bessel functions, Legendre polynomials, and Fourier transforms lacking.
What're some good references for these things?
Homework Statement
Given the Lagrangian
\mathcal{L}=\frac{1}{2} ( \partial_{\mu} \Phi)^2-\frac{1}{2}M^2 \Phi ^2 + \frac{1}{2} ( \partial_{\mu} \phi)^2-\frac{1}{2}M^2 \phi ^2-\mu \Phi \phi \phi,
[The last term, the interaction term allows a \Phi particle to decay into 2 \phi particles...
Hello,
I was reading about big bang nucleosynthesis recently (If it helps, I'm using Mukhanov) and it was calculating the abundance of neutrons. It seems to say that X_n→X_n^{eq} (It says that X_n^{eq} is the equilibrium abundance of neutrons) as t→0. So...does that mean that the neutrons...
Oh I see. So we use it because it works?
So the particle that couples to the U(1) is not the photon but another boson? And when mixed, it gives the photon and the Z boson?
Does that have any relation to the fact that U(1) corresponds to weak hypercharge and not electric charge?