Symmetry Definition and 907 Threads

Does electroweak symmetry breaking involve quantum tunneling, just like GUT symmetry breaking?

This article is about using P wave symmetry for super conductors, can you explain what a P wave is and why it is needed for super conduction please https://www.sciencedaily.com/releases/2017/01/170119084619.htm

Hi all, I'm studying electroweak spontaneous symmetry breaking at that time, see for instance Chang and Li's book ch 11. Have anyone an idea that if the charge operator is defined by: ## Q = \int (- e^\dagger e + \frac{2}{3} u^\dagger u - \frac{1}{3} d^\dagger d ) d^3 x ,## and the isospin...

(i am new and posted this in a Discussion area, it probably belongs here as I noticed marcus posts here. moderators, please delete the other message. my apologies) I am working on a contest question: In a causally connected universe how can one break symmetry if one assumes symmetry at one...

1. Homework Statement I want to show that the non-trival zeros of the Riemann Zeta function all lie in the critical strip ## 0 < Re(s) < 1## and further to this that they are symmetric about the line ##Re(s)= 1/2 ## where ## \zeta(s) = \sum\limits^{\infty}_{n=1}n^{-s}## With the functional...

Hello, I will be attending an undergraduate course called "Theoretical Physics" and I want to borrow some books from the library that cover the material of this course. I would appreciate any suggestions. The syllabus of the course is the following(I will be translating so I am sorry If...

I'm confused about the need for a fourth fundamental circuit element. I learned that the idea of the memristor was conceived by observing the symmetry of the equations for charge, flux, current and voltage. We have, i=dq/dt , v=dphi/dt. Rrom the three elements: dV=Rdi, dphi=Ldi, and dq=Cdi...

In spontaneous symmetry breaking, you expand the Lagrangian around one of the potential minima and write down the Feynman rules using this new Lagrangian. Will it make any difference to your Feynman rules if you expand the Lagrangian around different minima of the potential?

Consider the lagrangian of the real scalar field given by $$\mathcal L = \frac{1}{2} (\partial \phi)^2 - \frac{1}{2} m^2 \phi^2 - \frac{\lambda}{4!} \phi^4$$ Disregarding snail contributions, the only diagram contributing to ## \langle p_4 p_3 | T (\phi(y)^4 \phi(x)^4) | p_1 p_2 \rangle## at...

Hi all My question: I have read: Topological Insulators: Dirac Equation in Condensed Matters But also I have read: Observation of a Discrete Time Crystal Is it different situations ?

Hi everyone, Currently, I am self-learning Renormalization and its application to PDEs, nonequilibrium statistical mechanics and also condensed matter. One particularly problem I face is on the conservation of symmetry of hamiltonian during renormalization. Normally renormalization of...

Homework Statement I need to gauge the symmetry: \phi \rightarrow \phi + a(x) for the Lagrangian: L=\partial_\mu\phi\partial^\mu\phi Homework EquationsThe Attempt at a Solution We did this in class for the Dirac equation with a phase transformation and I understood the method, but...

I was reading Armstrong's Groups and Symmetry the other day and saw this table. It has beautiful symmetry. It is the the prime numbers multiplied modulo 8. It creates one of the most elegant things I've ever seen. What is so special about modulo 8 that creates such a symmetric matrix of primes?

How does a particles symmetry effect the way it behaves? Do particles with similar symmetry interact with each other in a special way than 2 particles with different symmetries?

Homework Statement Let ##\left|\psi\right\rangle## be a non-degenerate stationary state, i.e. an eigenstate of the Hamiltonian. Suppose the system exhibits symmetry for time inversion, but not necessarily for rotations. Show that the expectation value for the angular momentum operator is zero...

The generators for the isospin symmetry are given by $$T_{+}=|\uparrow\rangle\langle\downarrow|, \qquad T_{-}=|\downarrow\rangle\langle\uparrow|, \qquad T_{3}=\frac{1}{2}(|\uparrow\rangle\langle\uparrow|-|\downarrow\rangle\langle\downarrow|),$$ where ##|\uparrow\rangle## and...

Hi, is correct to say that there is no interaction between four photons because the gauge group of QED is U (1) while there are interactions of four gluons or four W's because the gauge group of QCD is SU (3) and EW's one is SU (2) xU (1)? I know that the interaction between four photons is not...

Hello! I am a bit confused about the relation between the singlet configuration and symmetry of the system. So in the spin case, for 2, 1/2 particles, the singlet configuration is antisymmetric. But I read that the quarks are always in a singlet configuration, which means that they are symmetric...

Superb, utterly superb. https://www.amazon.com/dp/3319192000/?tag=pfamazon01-20 Got my copy this morning. Only quibble is I would have done relativity this way: http://www2.physics.umd.edu/~yakovenk/teaching/Lorentz.pdf But what was chosen is still good. QM is developed from symmetry, the...

i used to get pauli matrices by the following steps it uses the symmetry of a complex plane sphere i guess so..? however i can't get the 8 gell mann matrices please help ! method*: (x y) * (a b / c d ) = (x' y') use |x|^2 + |y|^2 = |x'|^2 + |y'|^2 and |x| = x * x(complex conjugate) this way...

I was thinking about the metric tensor. Given a metric gμν we know that it is symmetric on its two indices. If we have gμν,α (the derivative of the metric with respect to xα), is it also valid to consider symmetry on μ and α? i.e. is the identity gμν,α = gαν,μ valid?

I am trying to learn about the various SU groups related to QCD. I have about 5 QFT and Particle physics books from my student library and written down about 20 pages of handwritten notes about specific parts of say generators, matrices, group properties etc. - but i don't really feel that I...

Some books prove CPT theorem basing on scalars,vectors, tensors building from 4-spinor of fermion and gamma matrices.Why can they do that?Because a general Lagrangian can contain bose scalar,bose vector,bose tensor fields and spinor fields. The CPT theorem says CPT symmetry is a strictly...

When immersed in a high-frequency sound, the rim of a wine glass oscillates as shown in the picture below. If the sound has equal intensity in all directions from the center of the rim, then where are the nodes of the stationary waves (in the rim)? By symmetry, every point on the rim is the...

If a force only depends on a radial distance "r" and it only has a radial component in the "er" then is it radially symmetric? This pertains to some homework problem I have, but part of the problem is that I'm not exactly sure what is meant by "radially symmetric". I assume its asking if the...

Hello, I was thinking about, how symmetry can be realized, when there is SSB occurring! Dont these terms contradict?

After 3 hours of google search. I found out scale symmetry is related to dimensional transmutation that can replace the supersymmetric particles that can solve the Hierarchy Problem of the Higgs (this is the hottest thing in LHC and physics right now). Scale symmetry is the key to understand all...

Hi, I am reading about this symmetry but I'm struggling to have a deep understanding of it. Would somebody please explain this symmetry to me from a conceptual point of view? Thanks in advance, Luca

I am doing a 2D Ansys workbench simulation ,it is nonlinear simulation due to frictionless contact, there is symmetry in the shape so I used the symmetry option to reduce the computation time and it succeeded to converge after that I tried the simulation of the whole body but it always fails...

I'm reviewing this book Warped Passages by Lisa Randall and a sentence caused me some incomprehension. Somewhere in it she stated: "The weak gauge boson masses tell us the precise value of the energy at which the weak force symmetry is spontaneously broken. That energy is 250 GeV, the weak...

Hi. I am looking for a QM book that covers symmetry , time-reversal , angular momentum representations in SO(3). I have a few books and most of them don't have much detail on these subjects.The main one that does is Sakurai. Any other suggestions ? Thanks

I suppose that my questions are pretty basic, but I've been trying to find out the answers and not succeeded. 1.- Do cosmologists really think that the vacuum state suddenly changed in the early Universe? If so, would it be like a phase transition? If so, first or second orther? 2.- Does the...

The quark sector of the QCD lagrangian can be written as (restricting to two flavours) $$\mathcal L = \sum_{i=u,d} \bar q_i ( i \gamma_{\mu} D^{\mu} + m) q_i .$$ Write ##q = (u d)^T## and $$M = \begin{pmatrix} m_u & 0 \\ 0 & m_d \end{pmatrix}$$ Given that the masses of the u and d quarks are...

CPT symmetry and antimatter gravity in general relativity M. Villata Published 28 March 2011 • Europhysics Letters Association EPL (Europhysics Letters), Volume 94, Number 2 Abstract The gravitational behavior of antimatter is still unknown. While we may be confident that antimatter is...

The Hamiltonian of an atomic electron is spherically symmetric so we expect to have symmetric distribution of electrons around the nucleus. However, as an example, p-orbitals don't have spherical symmetry and p_x-orbitals imply that electrons may be found in the x-direction with higher...

Consider a photon undergoing pair production and turn into a particle-antiparticle pair. Now play this in reverse, you got a particle and an antiparticle colliding to create a single photon. But in annihilation, the result is two or more photons. Violation of T symmetry? There also seems to be...

Hi, As I know we now think that time translation is not a symmetry of spacetime because of the Big Bang, so we cannot say that our physical laws are applicable at every point in time. But then isn't the developing of the Big Bang theory against this asymmetry?

Is \frac{\partial}{\partial t} an operator on Hilbert space? I'm a little confused about the symmetry between spatial coordinates and time in relativistic QM. There is a form of the Dirac equation that treats these symmetrically: i \gamma^\mu \partial_\mu \Psi = m \Psi However, at least in...

I read that CP-symmetry violation occurs (or can occur) in beta decay. Does that mean that, since CPT-symmetry must hold, there is no T-symmetry?

Heisenberg model of ferromagnet is defined by \hat{H}=-J \sum_{\langle i,j \rangle} \vec{S}_i \cdot \vec{S}_j where ##J>0## and summation is between nearest neighbours. Hamiltonian is perfectly rotational symmetric. However, the ground state “spontaneously” chooses a particular orientation...

I have been studying the method of symmetry from some days, which essentially reduce the effort needed for the evaluation of equivalent resistances. My textbook states: Points having symmetrically located about initial and final points have the same potentials.So, the resistances between these...

For inorganic chemistry, I am being asked to draw the solid state structure of polonium which i know how to do. However it asks what the symmetry of the unit cell is, and I don't know how to answer. I know what a unit cell is, I'm just not sure what the question means, or what it is looking for...

Could you explain why an H2O that attacks Ni(CN)4 ^(2-) (in square planar) (which has D4h symmetry) at one of the axial sites would have A2u symmetry? I know that the "HOMO" for the p orbital of the H2O would be a p orbital. I also tried to link that electron pair to an irreducible...

What other theories this number make impossible or improbable. When final number was given I hear some older physicist saying for one " 40 years of works gone" second grinding "only 30 for me!" We are ask to follow establish science. Seem to me that lots of theories was built on other's ones and...

I am looking for books/papers pertaining to symmetry principles in physics. I am particularly interested in literature aimed at deriving physical theories from their underlying symmetries, but all recommendations are welcome. I already know of the books Symmetries in Fundamental Physics by...

Consider a system of two identical spin-1 particles. Find the spin states for this system that are symmetric or antisymmetric with respect to exchange of the two particles. (Problem 13.3, QUANTUM MECHANICS, David H. McIntyre) I know that for bosons, the total wavefunction should be symmetric...

Homework Statement A simple classical example that demonstrates spontaneous symmetry breaking is described by the Lagrangian for a scalar with a negative mass term: ##\mathcal{L}=-\frac{1}{2}\phi\Box\phi + \frac{1}{2}m^{2}\phi^{2}-\frac{\lambda}{4!}\phi^{4}##. (a) How many constants ##c##...

Hello! I read about the symmetry of the following product $(x+a+b)(x+b+c)(x+c+a)$ my book says that a, b and c occur symmetrically. Why is that?

Homework Statement Consider the infinitesimal form of the Lorentz tranformation: ##x^{\mu} \rightarrow x^{\mu}+{\omega^{\mu}}_{\nu}x^{\nu}##. Show that a scalar field transforms as ##\phi(x) \rightarrow \phi'(x) = \phi(x)-{\omega^{\mu}}_{\nu}x^{\nu}\partial_{\mu}\phi(x)## and hence show that...

Homework Statement Verify that the Lagrangian density ##\mathcal{L}=\frac{1}{2}\partial_{\mu}\phi_{a}\partial^{\mu}\phi_{a}-\frac{1}{2}m^{2}\phi_{a}\phi_{a}## for a triplet of real fields ##\phi_{a} (a=1,2,3)## is invariant under the infinitesimal ##SO(3)## rotation by ##\theta##, i.e...