TransWikia.com
  1. All Categories
  2. Physics

Physics : Recent Questions and Answers (Page 93)

Find answers to your questions about Physics or help others by answering their Physics questions.

When should we consider "reverse Heisenberg" evolution of operators?

In Quantum Mechanics, the Heisenberg evolution of an observable $hat{o}$ is defined as $$ hat{o}(t) = U(t,0)^{dagger} hat{o} U(t,0) $$ where $U(t,0)$ is the unitary time-evolution operator...

Asked on 08/26/2021

1 answer

How does the quantum teleportation protocol not violate the no-cloning theorem?

Consider the following protocol:Alice and Bob share the statebegin{equation} |Phi^+rangle=frac{1}{sqrt{2}}(|0rangle|0rangle pm |1rangle|1rangle) end{equation}Alice has to teleport to Bob the state (which can be unknown even to her)...

Asked on 08/26/2021

1 answer

Local gauge transformation in Fock space of charged particles

I'm currently fiddling around with gauge-phase-transformations in Fock space.Especially, I'm trying to write a local gauge-phase-transformation asan operator in a basis-independent way. Here is what I have so...

Asked on 08/25/2021 by Thomas Fritsch

1 answer

Pressure at some different points with the same heights

Why do the red points in the following figure have the same pressure?...

Asked on 08/25/2021

1 answer

Normal Order of Normal Order

In the first volume of Polchinski page 39 we can read a compact formula to perform normal-order for bosonic fields$$:cal F:~=~underbrace{expleft{frac{α'}{4}∫mathrm{d}^2zmathrm{d}^2wlog|z-w|^2frac{δ}{δφ(z,bar z)}frac{δ}{δφ(w,bar zw)} right}}_{:=mathcal{O}}cal F, tag{1}$$...

Asked on 08/25/2021 by MaPo

2 answer

What happens to conservation laws if the spatial variable is complex?

This is more of a conceptual question. Normally a conservation law will look something like $$frac{partial j}{partial t}+frac{partial F}{partial x}=0tag{1}$$ where $x$ is typically a real-valued coordinate, or...

Asked on 08/25/2021 by user41208

1 answer

Are all gapless acoustic magnon modes essentially Goldstone modes?

We know gapless Goldstone mode appears when the system exhibits spontaneously symmetry broken. Does this means whenever we observe gapless acoustic modes it is Goldstone mode i.e. spontaneous symmetry broken?...

Asked on 08/25/2021

1 answer

Difference between QFT In curved spacetime, semiclassical, and quantum gravity?

Could someone describe the difference, qualitatively, between QFT in curved spacetime, semiclassical gravity, and quantum gravity? I know that each is an approximation to the next and the end goal...

Asked on 08/25/2021 by user203234

1 answer

Are following statements valid for quantum gravity?

In the concluding section of this post user Chiral Anomaly states following:On the other hand, since any stable marriage of quantum theory and gravity (in the sense of general...

Asked on 08/25/2021

1 answer

Derivative of Riemann tensor respect to Riemann tensor

I know that, for example we have $$frac{delta g^{jk}}{delta g^{lm}}=delta^{j}_{(l}delta^{k}_{m)}.$$This topic was discussed previously e.g. on Physicsforums.com and on Phys.SE. So I was wondering,...

Asked on 08/25/2021 by Alabarda 980

0 answer

Ask a Question

Get help from others!

© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP