Recent content by MarkovMarakov

Thank you, everybody!

Perhaps I should impose the condition of constant curvature...? Is that enough?

What is the most general form of the metric for a homogeneous, isotropic and static space-time? For the first 2 criteria, the Robertson-Walker metric springs to mind. (I shall adopt the (-+++) signature) ds^2=dt^2+a^2(t)g_{ij}(\vec x)dx^idx^j Now the static condition. If I'm not mistaken...

This question is on the construction of the Einstein Field Equation. In my notes, it is said that >The most general form of the Ricci tensor R_{ab} is R_{ab}=AT_{ab}+Bg_{ab}+CRg_{ab} where R is the Ricci scalar. Why is this the most general form (involving up to the second derivative...

I can't see how to get the following result. Help would be appreciated! This question has to do with the Riemann curvature tensor in inertial coordinates. Such that, if I'm not wrong, (in inertial coordinates) R_{abcd}=\frac{1}{2} (g_{ad,bc}+g_{bc,ad}-g_{bd,ac}-g_{ac,bd}) where ",_i"...

Thanks, WannabeNewton :) This is very helpful!

I would be very grateful if someone would kindly explain this generalization of the Lorentz force law to the special relativity domain. I am not entirely sure if what I have jotted down is exactly as the speaker intended to convey. But here is what I have got. Please bear with me...

@DaleSpam: the proper time is that of the emitter. I am still not sure how to do the substitution though. (Sorry about my daftness. :( )

@DaleSpam: LaTex fixed. I suppose u_e would be in terms of t_e,r_e measured by the emitter, no? But then what is its explicit form?

@DaleSpam: You are right. I have missed out the subscript e. I meant u as measured by the emitter.

Let's say we are working with the Schwarzschild metric and we have an emitter of light falling into a Schwarzschild black hole. Suppose we define the quantity u=t- v where dv/dr= 1/(1-r_{s}/r) where r_s is the Schwarzschild radius. What is the u as observed by the emitter? I just need a...

Homework Statement If there is a change of variables: (\vec x(t),t)\to (\vec u=\vec x+\vec a(t),\,\,\,v=t+b) where b is a constant. Suppose I wish to write the following expression in terms of a gradient in (\vec u, v) \nabla_\vec x f(\vec x,t)+{d^2\vec a\over dt^2} How do I do that? Homework...

ADDED: p is such that p\to \pi^-+\rho^+ and p\to \xi+\xi where \xi is a particle of spin 0. I want to know the lowest possible spin for p. I am assuming that conservation of total angular momentum and parity holds. By the way, would the intrinsic parity of p be negative, since I think each of...

Does the following argument correct? Suppose there is a particle $p$ that can either decay into $ \{$a spin-1 and a spin-0 particle$\}$ or two spin-0 particles, then the lowest possible spin of $p$ is 2. This is because we need the spin to be even and large enough to accommodate the spin-1...

Indeed!