# Search results

1. ### I Can someone expand (curlA.del)(curlA)

is there a simpler expansion of ((∇xA).∇)(∇xA). This is a common term in fluid equations.
2. ### I Quantum Entanglement-Susskind-lecture 4&5

In Lecture 5 on quantum entanglement, Susskind calculates the Bell's inequality terms using projection operator (a difficult concept and a tedious derivation). However, I believe the following I obtained the result on the Bell's inequality using the probability of spin of an electron prepared...
3. ### A Nonlinear first order Differential equation

I need to solve the well known momentum equation in 3D cylindrical coordinates: ρ(∂v/∂t +(v.∇)v)=A where A and the velocity v are both local vector variables. I am actually looking for the stationary solution to the equation, i.e. no ∂/∂t term) I have tried evolving the velocity and tried...
4. ### Flux surface average for a tokamak

I am trying to figure out the flux surface average of a 3D perturbation in a tokamak. For example what is the flux surface average of cos(m*theta+n*phi) at a given flux surface. (Theta and phi being poloidal and toroidal angles respectively?
5. ### Don't quite Understand the terminology -- Local gauge

I hope someone with a deep conceptual understanding of terminologies would help me out here. I am having starting problems in understanding the approach of gauge theories. I have read suggested threads and I am still at a loss. I am an experimental physicist and know basics of electrodynamics...
6. ### Consequence of Making a Higgs particle

Now we are presumably creating (?) Higgs Bosons in the collider. But the universe is permeated already by the Higgs field and Higgs bosons. When the colliders make an "artificial" Higgs, what conservation laws (in addition to energy, momentum, charge, isospin, baryon number etc.)are obeyed? In...
7. ### Velocity Cone in expanding universe

The figures in http://www.astro.virginia.edu/class/whittle/astr553/Topic16/t16_light_cones.html are very useful in understanding the various world lines in concordant diagrams. Is there any easy way to see how a velocity cone (at the observer's worldline) from a later time than the Big Bang...
8. ### Early Universe scalar field, inflaton and analogies in electric field

I have been trying to get my head around this topic for a while. As I go through the description of scalar fields, the inflation and the potential inflaton, (in description as in ned.ipac.caltech.edu), I constantly miss a concept. There must be a fundamental difference between the type of...
9. ### Flat Universe, dark energy and accelerating expansion

The CMB data suggests that the Universe is flat with in 0.4%. CMB data also shows that the expansion of the Universe is accelerating (from the sum of angles of triangle formed by distant hot spots- Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess). The pushing out dark energy is about 74% of...
10. ### Parallel transporting of a vector in curved space

Am I correct in saying that the angular deficit (change in angle) of a vector transported around a closed surface on a curved surface can only be observed by flattening the surface? Actually a further problem- I understand it from the flat sheet to a cone: Cut out a pie from a sheet, Draw a...
11. ### Confused-Aharanov-Bohm Effect

Gauge theory says that Potential not field strengths are fundamental in a force field. Aharanov- Bohm experiment showed that charged particles changed characteristics (phase) when placed inside a shielded box with zero electric and magnetic fields, but a non-zero potential outside. But gauge...
12. ### Angular Momentum conserved but not energy?

New to the forum- looked through the forum, but all are tangential answers. A skater with mass m, is spinning with arms extended to radius r1, with a tangential speed v1, angular velocity w1; v1=w1*r1, angular momentum mv1r1 =mw1r12; kinetic energy 1/2 m1v12. Now she pulls in her arms to a...