Recent content by sayebms

Homework Statement (a) Calculate the Conserved currents $$K_{\mu \nu \alpha} $$ associated with the global lorentz transformation and express them in terms of energy momentum tensor. (b) Evaluate the currents for $$L=\frac{1}{2}\phi (\Box +m^2)\phi$$. Check that these currents satisfy...

After much thinking I have found that we need to use the equation for tidal forces acting on the spaceship as it approaches the star. and it appears that there is a big difference (a few hundred g's if i remember correctly) in gravitational acceleration between tip of the spaceship and its tail...

this is a small part of a problem on tidal forces and I wasn't sure what the question asks as it seems to me that more information is needed. Am I right or is there something I am missing? the question goes as: "A spacecraft approaches a neutron star of radius 10 km and mass 1.5 times mass...

so using the Hamiltonian equations of motion I have: $$\dot{Q_1}=\frac{\partial H}{\partial P_1}=aP_1 \Longrightarrow \frac{d(q_1^2)}{dt}=2q_1\dot{q_1}=aP_1\\\dot{Q_2}=\frac{\partial H}{\partial P_2}=b \Longrightarrow \dot{q_1}+\dot{q_2}=b\\\dot{P_1}=0\\\dot{P_2}=0$$ So I guess these are the...

Homework Statement Point transformation in a system with 2 degrees of freedom is: $$Q_1=q_1^2\\Q_2=q_q+q_2$$ a) find the most general $P_1$ and $P_2$ such that overall transformation is canonical b) Show that for some $P_1$ and $P_2$ the hamiltonain...

Thank you so much I have found it. it will be as following: the four momentum of system after the collision and creation of two identical particle will be: $$p^{\mu}_T=(2 \gamma mc,0,0,0)$$ now using $$\gamma=1$$ and using the invariance of the square of the total momentum in a reaction we get...

Then how do we do we solve the last part (part d), I thought i was going to need it for determining the minimum energy.

Can we use the Lorentz boost ti find it? I mean looking for a transformation that makes the spatial components of the total four momentum vanish?

Homework Statement Two photon of energy ##E_1 ## and ## E_2## collide with their trajectory at an angle $\theta$ with respect to each other. a) Total four-momentum before collision? b) square length of 4-momentum in lab frame (LB)and in center of momentum frame (CM)? c) 4-momentum of two photon...

Homework Statement A potential satisfies ##\nabla^2 Φ = 0## in the 2d slab ## -\inf < x < \inf ##, ##-b < y < b ##, with boundary conditions ## Φ(x, +b) = +V_s(x)## on the top and ##Φ(x, b) = -V_s(x)## on the bottom, where[/B] ##V_s (x)= -V_0 for -a<x<0## ##V_s (x)=+V_0 for 0<x<a## (a) what...

I have actually found out a way to do it, its not through bessels functions though. but thank you for the help

should I solve it without the resolution of Identity?

since the problems says for every state A so should I write as following ##<A_i|L|A_i>=0 \to ## then as before ## <B_j|L|A_i>=\sum_{i}<B_j|A_i><A_i|L|A_i>=0## is it right now?

Homework Statement Suppose a linear operator L satisfies <A|L|A> = 0 for every state A. Show that then all matrix elements <B|L|A> = 0, and hence L = 0. Homework Equations ##<A|L|A>=L_{AA} and <B|L|A>=L_{BA}## The Attempt at a Solution It seems very straight forward and I don't know how...

Homework Statement A potential ##\phi(\rho, \phi ,z)## satisfies ##\nabla^2 \phi=0## in the volume ##V={z\geqslant a}## with boundary condition ##\partial \phi / \partial n =F_{s}(\rho, \phi)## on the surface ##S={z=0}##. a) write the Neumann Green's function ##G_N (x,x')## within V in...