Fields Definition and 1000 Threads

Homework Statement Two charged particles (P & Q) are fired into a uniform magnetic field that is directed into the page. When a particle possessing charge q moved through a magnetic field B at a velocity v it experienced the lorentz force that has a magnitude of F=qvB. What is the sign of P...

Hi, are there any math texts out there that are good introductions to operator fields as used in quantum field theory ("fields" in the physics, not mathematical sense, in this case.)?

I'm trying to re-derive a result in a paper that I'm struggling with. Here is the problem: I wish to calculate (\nabla \otimes \nabla) h where \nabla is defined as \nabla = \frac{\partial}{\partial r} \hat{\mathbf{r}}+ \frac{1}{r} \frac{\partial}{\partial \psi} \hat{\boldsymbol{\psi}} and...

Homework Statement An electron traveling horizontally east passes between two horizontal, oppositely charged plates and is deflected downward. Part A: Passing through the same space between the plates, in what direction (if any) a proton traveling horizontally east would be deflected? Part B...

What fields or branches of physics are most researched today? Which has the most unsolved mysteries?

I've been told that magnetic field does not mask or influence any GHz transmissions; TV, Radio, Wi-Fi, etc. and should not pose a problem. Can someone explain why they do not interact? Credible documentation such a law or theory? Educational documentation? Thanks in advance.

My question is simple; yet, I can not find the answer. In the picture below, all variables are identical; the plate separations, surface area, etc. The only difference is the fact that example 1 has 2 different dielectrics. Better yet, it has a dielectric that doesn't extend the entire distance...

Can anyone help with an ongoing argument we are having. When a particle interacts with a vector field e.g. the electric field, it experiences a force trying to move it which depends on the particle charge and the local field condition, - but when it interacts with a scalar field e.g. the Higs...

Based on what I have learned, I know that a theoretical physicist has to work in a specific field. But can one work in two? For instance, a person who has a PhD in cosmology but is working on both cosmology and field theories (quantum, unified). Or maybe even the same person working at a...

Homework Statement We are giving to lines: r1(t)=<1-t,4,5+2t> r2(s)=<2,1+s,-s> 1. Find an equation perpendicular to the two lines and passing point P(1,1,1) 2. Find Coordinates of points of intersection of the line found in #1 with planes x=-1, xz-plane 3. Parametrize the line segment joining...

I'm in high school, thinking about what I want to do in college. I am aiming to get some sort of PhD in Theoretical Physics. I would love to just get one in general theoretical physics, but I am unsure if that is offered. I know that I can go into specific areas such as particle or field...

Are a field and its complex conjugate independent? It seems like they're not, as one is the complex conjugate of the other, so if you have one, you know the other. However, it seems in path integrals, you integrate over the field and its conjugate, so they can take on values that are not the...

According to page 61 'Einstein' by Andrew Robinson an electric charge at rest produces no magnetic field. But: For an observer moving East with uniform motion the charge will appear to be moving West uniformly and B, using a sensitive compass, will detect a magnetic field around the 'moving'...

Homework Statement I'm reading Peskin and Schroeder to the best of my ability. Other than a few integration tricks that escaped me I made it through chapter 2 with no trouble, but the beginning of chapter three, "Lorentz Invariance in Wave Equations", has me stumped. They are going through a...

Entering my third year of my bachelor of science majoring in maths/physics and having some trouble deciding what courses to do this semester. I know for sure I will be taking complex analysis and 3rd year quantum however am having trouble picking between 3 in particular for my final two courses...

I should add context to this question that what I know so far of the emf is that it is defined as ##\mathscr E=\oint f \cdot d\ell## where ##f## is the sum of the forces on the charges. In the textbook I'm reading it gives an example of where a person pulls a rectangular wire with a velocity...

Why are electric and magnetic fields in an electromagnetic wave in phase? Can somebody please explain that?

Does anyone know of fields (with additional structure/properties) other than either ##\mathbb R, \mathbb C ## that are "naturally" manifolds? Thanks.

i am having some trouble with understanding the magnetic fields inside transformers and how they relate to back emf. In particular, I am considering the two cases of current passing through the primary coil but not the secondary coil, and then with the secondary coil as part of a complete...

I'm not quite following why Wick's Theorem only applies to free fields. What part of the argument depends on a free field assumption?

Let me give you an example of a reasoning I made in a simple case. Afterwards comes the question: Start of reasoning. Consider two standard ideal capacitor plates with a dielectric material in between them. Let's call the external field caused by the plates ##\vec{E_{ext}}## and the average...

Good day everyone! n00bie here. I did do a search before I posted this... found a lot of info, most of which I couldn't apply to what I am doing (because I wouldn't know how). I have something that I am working on that creates an electric field to alter certain chemical compounds. The distance...

I was wondering. What's the reason for putting objects in low representations in the SM and not higher ones? So, why fermions in a doublet of SU(2) and not a multiplet? In analogy in SU(5) we put the particles in the 5-plet...

Is magnetic field conservative or non- conservative field? I think that it should be conservative but not sure.

I have some questions with regards to conjugate points on a congruence of time-like geodesics (will be referring to Wald 9.3 throughout). First, we define ##\gamma## to be a time-like geodesic with tangent ##\xi^a## parametrized by ##\tau## and with ##p\in\gamma##. We consider the "congruence of...

I hope this isn't deleted for "personal theory" reasons because it's really just a discussion point. I just have to give two paragraphs of preamble before getting to the point. To me, an oversaturated field is one in which there are too many qualified people for the number of quality jobs...

Hey guys; I'm looking for info on the maximum power transfer using the magnetic induction method. The current through a coil, then catch the mag field with another coil idea. Mainly looking for high energy transfer methods, maybe some equations that describe it. A friend and i are playing...

Imagine you have an electron traveling at high speeds... would you expect it´s EM field to be contracted following the Lorentz transformations?? If the answer is no, please explain why fields and their shape don´t deform when space-time does. How they retain their shape in a space that is not...

In electrostatics, ∇ × E = 0 so E that is a conservative field and there must be sources of E from which E flows. We know that this sources are the electrical charges given by Gauss' Law. But when B changes in time, ∇ × E = - ∂ B / ∂t. Now the Gauss' Law no longer applies and if there are not...

I was reading about the Klein Gordon equation of scalar fields. I notice that the hamiltonian is not Hermitian: ∂0(Φ,π)T = matrix((0,1),(-p2,0)) (Φ,π)T The Hamiltonian operator iH = matrix((0,1),(-p2,0)) is not a hermitian matrix. What does this mean? Does this mean Klein Gordon fields don't...

I read in an article that a quantum field is one where every point in the field is defined by an imaginary number. If you square the imaginary number you get a wave function. But can a three dimensional field be defined by a set of points, finite or infinite? Does it mean a field characterized...

Homework Statement A cathode-ray tube aims electrons parallel to a nearby wire that carries current in the same direction. What will happen to the cathode rays in terms of deflection? The Attempt at a Solution [/B]The Motor force deflects the cathode rays ?

Let's say there's a question where there are two charges placed, and a point in between and above the line connecting the two charges forms a triangle like this: http://session.masteringphysics.com/problemAsset/1413940/2/p19.5.jpg What would one have to do in order to find the electric field...

Homework Statement Two parallel conductors each carry 10 A of current in the same direction. a) What is the magnetic field strength at the midpoint between these wires? (answer = 0T) b) What is the field strength at the same point if the current ran in opposite directions? (answer = 4.0x10^-4T)...

Homework Statement Demonstrate the equivalence between the gauge fields A1=(0,bx,0) and A2=)-yB/2,xB/2,0) and find the scalar field Φ for which A1= A2 + ∇ΦHomework Equations B = ∇XA The Attempt at a Solution The first part is fine, you just plug it into the above relevant equation and you get...

If we consider E and B individually, there are 6 total degrees of freedom. But they are actually related to each other by Maxwell's equations. So we can find potentials and reduce dof to 4; 3 in vector potential and 1 in scalar potential. Thus, there remain 2 redundant dof. This is the...

Hi, Am I correct in thinking that for a positively charged spherical electrode, the charge is distributed radially from the entire surface of the sphere, and as such, the electric field is distributed in this way too? If an earthed electrode is then placed nearby, a high voltage would be...

In http://arxiv.org/abs/hep-th/9506035 the author said after writing this equation: $$\frac{1}{4}\eta^{\mu\nu\lambda\rho} F_{\mu\nu}F_{\lambda\rho} = \eta_{\sigma\tau\alpha\beta}\frac{\partial L}{\partial F_{\sigma\tau}} \frac{\partial L}{\partial F_{\alpha\beta} } + 2C$$ where C was arbitrary...

Hi If anyone has job prospect info, statistics or anything about these, please tell. Thanks a lot Energy and Fluid Systems Manufacturing and Dynamic Systems Materials Engineering

Hello! I hope I posted this in the right section. I have tried to google the definitions of what follows but I didn't get what I expected. I would like to ask you then: What is the definition of a self-dual field and a self-dual topologically massive vector gauge field? Thank you very much...

When a moving proton travels through a magnetic field, doe's it's magnetic field (that it's giving off) naturally align with the outside magnetic field (due to a magnet or something in the environment)?

I am a senior physics BS student, applying to programs in condensed matter and high energy physics at the moment. However, I have always been interested in doing an MS in EE. Its sort of late this year though, and I can't apply for EE programs now. But that got me thinking: is it possible to...

In the Einstein-Hilbert action wikipedia page, the following paragraph is written: I thought for treating spin, we need to consider Einstein-Cartan theory! This is really surprising to me. Can anyone suggest a paper or book that explains this in some detail? Thanks

Hey! :o I have to show that $\mathbb{F}_{2^2}=\mathbb{Z}_2(a)$, where $a \in \mathbb{F}_{2^2}$ is of degree $2$ over $\mathbb{Z}_2$. Could you give me some hints how I could show that?? (Wondering)

Hi guys, So I have the following Lagrangian: \mathcal{L}=\bar{\psi}(i\partial_{\mu}\gamma^{\mu}-m)\psi+\frac{1}{2}(\partial_{\mu}\phi)(\partial^{\mu}\phi)-\frac{M^{2}}{2}\phi^{2}-\lambda\bar{\psi}\psi\phi where m is the is the mass of the spin-half Dirac field and M is the mass of the spin-0...

Is a one-dimensional gravitational field possible? I'm not sure if I'm using the correct terminology, what I mean is instead of pulling things into its center of gravity it pulls things in the same linear direction until it ejects it out.

Over seven years ago, I was homeless for a period of time. During this time, i was arrested twice and convicted twice for theft under $500 dollars. In both instances I only stole food to feed myself (although I don't believe it matters, as I imagine it isn't reflected on the record). Since then...

My first question from his first volume. On page 254, he writes down the action expression: (3-10.1)W=\int (dx)[K\phi+K^{\mu}\phi_{\mu}+\mathcal{L}] Where the lagrangian is: \mathcal{L}=-\phi^{\mu}\partial_{\mu} \phi +1/2 \phi^{\mu}\phi_{\mu} -1/2 m^2 \phi^2 The consideration of...

Say I have a large spacetime lattice set up on a supercomputer where I calculate the scattering cross section of two spinless electrons of equal and opposite momentum via lattice QED. To get the right results we must add the amplitudes for every possible "path" the field can evolve from initial...

Hello! (Wave)I have to check if the equation $3x^2+5y^2-7z^2=0$ has a non-trivial solution in $\mathbb{Q}$. If it has, I have to find at least one. If it doesn't have, I have to find at which p-adic fields it has no rational solution.Theorem: We suppose that $a,b,c \in \mathbb{Z}...