How Can a Generic Vector Be Decomposed Using the Helmholtz Theorem?

AI Thread Summary
A generic vector can be decomposed into an irrotational component and a solenoidal component using Helmholtz's Theorem, expressed as V(r) = -Grad[phi(r)] + Curl[A(r)]. To demonstrate this decomposition, one should take the divergence and curl of the vector V and apply relevant vector identities. The divergence of the irrotational component yields a scalar function, while the curl of the solenoidal component is zero. The discussion concludes with the realization that using projection operators can simplify the proof of this decomposition.
Legion81
Messages
68
Reaction score
0
I have to show that a generic vector can be decomposed into an irrotational and solenoidal component:

V(r) = -Grad[phi(r)] + Curl[A(r)]

I'm not sure how to start. Do I need to take the curl or div of V and use a vector identity? Any help would be greatly appreciated!
 
Physics news on Phys.org
Helmholtz' Theorem starts with the two components in my original post and defines the divergence and curl as:

div[V] = s(r)
and
curl[V] = c(r), where div[c(r)] = 0

But I can't find anything about how we can define a generic vector as two components:

V = -grad[phi] + curl[A], where "phi" is the scalar potential and "A" is the vector potential. I need to do this before I can show that s(r) and c(r) uniquely specify the vector.

I hope that makes my problem a little more clear.
 
Legion81 said:
I have to show that a generic vector can be decomposed into an irrotational and solenoidal component:

V(r) = -Grad[phi(r)] + Curl[A(r)]

I'm not sure how to start. Do I need to take the curl or div of V and use a vector identity?

Taking the divergence/curl of both sides of this equation seems like a good place to start. What do you get when you do that?

P.S. You may wish to use boldface font to denote vectors, to make things clear.
 
I actually just found an easy way of showing it using projection operators. Thanks for the reply.

Consider this question solved.
 
Thread 'Help with Time-Independent Perturbation Theory "Good" States Proof'
(Disclaimer: this is not a HW question. I am self-studying, and this felt like the type of question I've seen in this forum. If there is somewhere better for me to share this doubt, please let me know and I'll transfer it right away.) I am currently reviewing Chapter 7 of Introduction to QM by Griffiths. I have been stuck for an hour or so trying to understand the last paragraph of this proof (pls check the attached file). It claims that we can express Ψ_{γ}(0) as a linear combination of...
Back
Top