Symmetry Definition and 907 Threads

Hello everyone, I'm a bit confused by something I've read as have been unable to find resources to clarify it. Here is the statement that confused me, from Binetruy's Supersymmetry textbook (p.26): It is well-known that [in the case of ordinary continuous symmetries] no possibility of...

If there were magnetic monopole, the Maxwell equations should be modified as \nabla\cdot\vec{B} = \mu_0\rho_m \nabla\times\vec{E} = - \frac{\partial \vec{B}}{\partial t} - \mu\vec{J}_m and plus the other two. I wonder how to prove these two modified equations are of correct...

Due to several threads, recent thinking and book readings, suggesting the the concept of "symmetry" itself, as well as the concept of "continuum" are somehow related to a key problem. I asked myself the question about the original line of reasoning of the introduction of symmetry historically...

Consider a system of two bosons with spin, say photons. The wave function must be symmetric under the exchange of the two particles. For example, |psi> = |up> |down> + |down> |up> So far, so good. Now let us measure the spin of the particles, and let the outcome of the measurement be that...

I've got a 3D shape that, um, inherits from a cube (i.e. it retains properties characteristic of cubes). It has high symmetry. I wish to string all its vertices (of which there are 16) with - I dunno, yarn - forming the edges (of which there are 32). I can do the entire thing with a single...

Hi Can someone please explain me what is the symmetry energy? I know asymmetry energy in the weizsacker semiempirical mass formula which is the gap between a nucleus and it's isobar with Z=N.

hello all gauge symmetries are redundencies of the description of a situation. Therefore they are not real symmetries. So in what sense does it mean to spontaneously break a gauge symmetry? ian

Homework Statement A cone of mass M has a height h and a base diameter R. Find its moment of inertia about its axis of symmetry Homework Equations I=\int R^{2}dmThe Attempt at a Solution I tried starting by finding dm. It's equal to the mass per unit volume, \frac{M}{\frac{1}{3}\pi R^{2}h}...

Homework Statement Could someone please just explain a step in a proof for me? Suppose x and y are symmetric with respect to a circle, and a,b and c are three points on the circle. This means that: (x,a,b,c) = (\bar{y},\bar{a},\bar{b},\bar{c}) The writer then says: "symmetry...

Hi there! As most people already might know, we can decompose the 27 dimensional representation for the baryons under SU(3) flavour symmetry as 27 = 10 + 8 + 8 + 1. I can find a lot of information about the particles that lie in the decuplet and in the octet, but nothing about which particle...

Please pardon this very newbie question: I am ploughing through Mayer's "The Many Directions of Time." He seems to assume right at the outset that Relativity is correctly interpreted as meaning that BOTH observers moving in constant velocity relative motion would be entitled to claim that the...

Hello I have to calculate symmetry factors for the following feynman diagrams for my qft class, and would be hugely grateful if anyone could point out any mistakes (I'm sure there are lots!) that I've made. http://picasaweb.google.com/jessicagreerstanley/Physics#5259179071440262450"...

Does the ever increasing nature of entropy violate time reversal symmetry?

Hi! Brief question: I wonder which conditions should a polynomial function of odd degree fulfill in order to be symmetric to some point in the plane. Are there such conditions?

Say we are looking at a positively charged rod with uniform charge density and a radius of R. When using Gauss' law and taking a cylindrical surface we use the formula E = lambda/2*pi*epsilon*r When we derive this equation we are assuming R is significantly smaller than L and so we...

hi, I have found a website in which it has described how to find high symmetry points for wurtzite structure. Here is its address: http://cmt.dur.ac.uk/sjc/thesis_mcg/node53.html But, as I know these points are being used for standard numbers of atoms for example in a wurtzite system we...

When the SU(2) symmetry is broken by the Higgs mechanism, the W bosons acquire mass and become the well-known W^+ and W^- bosons discovered at CERN. So before the breaking, the Ws had no mass. Did they have charge? If yes: No particle is known without mass but with charge. Are the W...

Hey Is it right that high symmetry molecules does not absorb light as good as low symmetry molecules? let's take an example like benzene versus benzene+hydroxyl?

Hi: What is Spontaneous symmetry breking ? and when does it happen.? Regards

The classic physics problem example of symmetry breaking is a pencil sitting directly on its tip (pointed down), but it's possible for the pencil to balance on its tip if we reduce the thermal fluctuations to zero by cooling it to close zero degree. Quantum fluctuations require/mean that...

Please look at the attached diagram and let me know if there is a reason for the asymmetric dynamics due to the relative position of rest or, if I have incorrectly interpreted the mechanics. Kev, I haven't forgotten.

I was reading the book "New Theories of Everything" and I came across the term "random symmetry breakings" Let me explain a bit: This applies if there are more than 3 spatial dimensions. In our early universe when our universe was very small, hot and dense, it would be safe to say that at one...

Suppose we drop a bottle cork on water. It has a shape similar to -rougly- a pyramid i.e. upper area A1 is smaller than bottom A2. Therefore it's vertically as well as horizontally symmetric. But as we drop it, it does not stay vertical but horizontal making upside and downside areas (A) equal...

Hey Im doing vibrational spectroscopy (Raman, nir, vis/uv) of a protein called C-reactive Protein. Its a symmetric molecule regarding the subunits http://en.wikipedia.org/wiki/C-reactive_protein Then i wondered if one can apply normal coordinate analysis (using symmetry and group theory) to...

Was the early spontaneous symmetry breaking caused by exponential expansion in the first instant of standard theory? Is that the reason that the early Big Bang universe is thought to have contained equal amounts of matter and anti-matter (produced by spontaneous symmetry breaking)? Does...

Is weak interaction invaraint under CPT Symmetry? Why?

i really can not understand it

I know it's just a mental block - for some reason I can't get the phrase "restoring force" out of the ongoing debate in my noggin. But this is a question about symmetry specifically, and the notion of a force appearing because of an asymmetry, or "symmetry-breaking". The simplest notion I...

Do you think you could give me some helpful insight to a follow up question from the discussion of defining inertial frames: I'm still having trouble figuring out a good way of incorporating parity violation into my intuition. If it wasn't for experiment showing otherwise, I probably would...

Local Gauge Symmetry ?? Trying to understand local gauge symmetry ================================ I have an undergraduate degree in physics, so I know basic quantum mechanics, but that's all. Still, I'm trying to understannd the concept of local gauge symmetry. I would appreciate if...

On spontaneous symmetry breaking and Higgs’s mechanism of mass production From lectures: L. Peak and K. Varvell. The Physics of the Standard Model. Full Lagrangian for fermion and photon Combine the gauge-invariant Lagrangian density describing a fermion field in the presence of an...

In chapter 4 of Bailin & Love, Supersymmetric gauge field theory and string theory, the authors state that supersymmetry is considered a global symmetry, and we can separately consider it to be a local symmetry. Further, since the supersymmetry algebra contains P^\mu, the generator of...

Determine whether the graph of the relation is symmetric with respect to the y axis, x axis, or the origin. y=(x-3)^{3} I don't know how to produce a visual of the graph with this post but it is a graph of y=x^{3} moved 3 units to the right along the x axis. Visual examination of the graph...

Is there a nice, cute way to see what R symmetry is? I mean, N=1 SUSY has a global U(1)_R symmetry, which is a charge carried by the supercharges, right? And a spontnaeously broken U(1)_R is a sufficient (but not necessary) condition for broken global SUSY. (Counter-example is O'Raifeartaigh...

I am taking a first course in Lie algebras and currently working with this problem (see attached file). I understand that the product of the two operators should be regarded as composition. How to explain the final expression? Regards Staffan

Can someone help me? It is correct at all to make the conection between the SU(3) symmetry and zeros of (radial) wave function? To make more clear: can I say that the fact that radial wave function has only the simple zeros automatically excludes the existence of SU(3) symmetry for given quantum...

I understand that all conservation laws have underlying symmetries and that all symmetries have corresponding conservation laws. From reading some popular science books (don't shoot me :P), I understand that conservation of energy, linear and angular momentum are a natural consequence of time...

For gravitation and any inverse-square forces, the Laplace-Runge-Lenz vector is conserved. (see http://en.wikipedia.org/wiki/Laplace-Runge-Lenz_vector" ) Any conserved quantity is associated with a symmetry of the Hamiltonian with respect to some coordinate, according to the Noether theorem...

Homework Statement 24 identical positive charges, each has a magnitude 2.0 microCoulombs equally spaced along a circle with a radius of 0.4 m which lies in the y-z plane. a)determine the electric field at a point 1 meter away from the circle's center along the x-axis. b) Find the...

I'm trying to understand Feynman diagrams interpretation in terms of virtual particles. What I still can't understand is how this interpretation is compatible with the fact that one should divide each diagram by its symmetry order. As far as I understand, diagram symmetry order means how many...

Homework Statement http://tng.trekcore.com/1.JPG I'm trying to prove that the circle is symmetrical by showing that x² + y² = a² holds when the circle rotates. I know that this is proved given the following two formulae: x = x'cosθ - y'sinθ y = x'sinθ + y'cosθ but I don't know...

What is the meaning of "spurion"? How can it break the symmetry? Which book give some good explanations about this theory? Thanks!

I conjecture that only spherical symmetric mass distribution can produce radial gravitational force field (according Newton's law of gravitation). Can anybody prove or disprove this conjecture?

Homework Statement http://avogadro.chem.iastate.edu/CHEM332/332Fall06Exam5Key.pdf Please go to page 5. Homework Equations No equations, just concepts. The Attempt at a Solution I tried the first problem (A), and got the solution wrong. I thought I'd check the concepts before attempting any...

Problem: How do you determine the line of symmetry of a reciprocal equation? Solution: For example, I'll graph the reciprocal function Y=1/(x+2) ^Just a quick sketch And the equation of the line of symmetry is simply -(x+2), which can be seen here: ^Also a quick sketch By adding a...

Homework Statement I'm doing a dissertation on heavy ion collisions and one of the things they look for in the collisions is chiral symmetry resolution - what is it? Homework Equations The Attempt at a Solution I understand that it is a type of symmetry that is usually broken...

hi What is symmetry? hi explain symmetry and symmetry breaking in details with example Regards Ryan

Noether's theorem relates symmetries and conserved quantities, eg. if the Lagrangian is invariant under a spatial translation, you have have conservation of momentum. For continuous systems, the conserved quantities become conserved "currents". Anyone know what symmetry is associated with...

Interesting new paper from John Moffat: http://arxiv.org/abs/0709.4269 Introduces a non-local, finite QFT that dynamically generates boson and fermion masses as loop corrections. Experimental evidence for the theory will be visible in WW scattering at the LHC (coupling goes to zero, which...

One difference between GR and LQG is that LQG is chiral, whereas GR is not. In order to break the electroweak symmetry, a higgs field needs to be introduced by hand. Einstein's understanding of inertia implies a strong EP as gravitational mass and inertia are identical, while a higgs...