Questions tagged [angular-momentum]
The conserved quantity arising from a rotational invariance. Combine with rotational-dynamics for the classical mechanics approach and quantum-mechanics for the QM interpretation
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Kepler's third law and conservation of angular momentum: apparent fallacy
Angular momentum $L$ of a particle in central force is a constant of motion. So for circular orbit, $$L =mωr^2 = constant.$$
This implies $$ω ∝ 1/r^2,$$ hence the time period of revolution, $$T = 2π/ω ...
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Problem in understanding the proof of Wigner-Eckart in Sakurai
if you write the recurrence as a homogeneous linear system $A\mathbf x=0$, a necessary and sufficient condition for proportionality of (nonzero) solutions is that $\dim\ker A=1$. For a simple ...
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What would Spin Operator and Spin State Vectors be in higher dimensions?
If we represent spin quantum state of a particle in $\pm z$ direction with $\vert\pm\rangle$ then we know that the state vectors in remaining $x$,$y$ directions would be such that:
$$\vert\langle S_x;...
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Is angular momentum generator a tensor in the Poincare group?
According to Weinberg' QFT vol I, (2.4.8), the generator of angular momentum $J^{\rho\sigma}$ transform as
$$U(\Lambda, a) J^{\rho \sigma} U^{-1}(\Lambda,a) =\Lambda_\mu^{\,\,\rho} \Lambda_\nu^{\,\,\...
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Is it possible to increase the rotation of a black hole without increasing the mass?
Imagine a very advanced civilisation that can spin and move neutron stars at will. It desires to increase the angular momentum of a black hole without increasing its mass.
Could they manipulate the ...
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If the universe is spinning now was it spinning faster in the past to conserve angular momentum?
If the universe is rotating once every 500 billion years, as some researchers think, and angular momentum is conserved, then when the universe had a smaller radius was it spinning faster?
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Why does a rotating, asymmetrical system tend towards a state that is symmetric?
When reading my textbook's chapter about angular momentum, I was told to consider the situation that is described in the diagram below. My textbook stated that if the connecting rod with masses on ...
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Veritasium rotating wheel angular momentum
In this Veritasium video, there is a rotating wheel attached to a rope hanging from ceiling by a rod connecting end of the rope to the center of the wheel.
I understand that if you know that a priori ...
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How To Start Learning Angular Momentum In QM? [closed]
So I have been tasked with to prepare a report on Density Matrices in QM. I am still a newbie. I want understand and learn physics. the books that arr prescribed to me right now are:
Angular Momentum ...
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Can spin really be measured in an arbitrary direction?
If I am in the computational basis (given by unit vector ${z}$) and have a ket $|0\rangle$, and I have $\sigma = (\sigma_x, \sigma_y, \sigma_z)$, the Pauli matrices, then my ket is an eigenfunction of ...
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Why is Angular momentum conservation used to explain the velocity of an electron in a specific orbit?
According to Bohr's Atomic Model, the formula for finding out the angular momentum of an electron, rotating in any particular orbit, i.e:
$$mvr = \frac{nh}{2\pi} \ ,$$
where $n$ = number of orbit, ...
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Observing $L_x$ of a particle which is present in an eigenstate of $L_z,L^2$
I wonder what will be the probability of finding the particle in a particular $L_x,L^2$ state after we know its $L_z,L^2$. Definitely,the $L^2$ value will not change. Here is what I tried:
First of ...
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Correcting the angular momentum in GR for non-point-like bodies?
Background
Consider I'm studying the orbit of planets using the Schwarzschild metric is given by:
$$
ds^2 = -\left(1 - \frac{2GM}{c^2 r}\right) c^2 dt^2 + \left(1 - \frac{2GM}{c^2 r}\right)^{-1} dr^2 +...
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Intuition about the angular momentum term in GR gravity
Using the Schwarzchild solution and taking proper units to make $r_s=c=1$, we can obtain that the geodesic of a test object orbiting a non-rotating uncharged black hole can be seen as being attracted ...
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Are these two notions of "conserved angular momentum" in axially symmetric spacetimes the same?
In Schwarzschild and Kerr spacetimes, when one studies the problem of a test particle undergoing geodesic motion, the use of symmetries is crucial in showing integrability and in solving the dynamical ...
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