Gauge Invariance in Hamiltonian

Click For Summary
SUMMARY

The discussion centers on the application of the product rule in the context of gauge invariance in Hamiltonian mechanics. Specifically, the divergence operator is applied solely to the vector field A, resulting in the expression ##(\nabla\cdot A)(e^{\lambda}\psi)## rather than the combined term ##\nabla \cdot (Ae^{\lambda}\psi)##. This distinction is crucial for understanding the behavior of the divergence operator in relation to scalar and vector fields. The participants clarify that the exponential term is treated as a constant during this operation.

PREREQUISITES
  • Understanding of vector calculus, specifically divergence and gradient operations.
  • Familiarity with Hamiltonian mechanics and gauge invariance concepts.
  • Knowledge of scalar and vector fields in physics.
  • Basic proficiency in mathematical notation used in physics, including exponential functions.
NEXT STEPS
  • Study the properties of divergence in vector calculus.
  • Research gauge invariance principles in quantum mechanics.
  • Explore Hamiltonian mechanics and its mathematical foundations.
  • Learn about the implications of product rules in differential operations.
USEFUL FOR

Students and professionals in physics, particularly those studying electromagnetism and quantum mechanics, as well as mathematicians interested in vector calculus applications.

Sagar Rawal
Messages
6
Reaction score
0

Homework Statement


Hello Everyone
I'm wondering, why in below product rule was not used for gradient of A where exponential is treated as constant for divergent of A and only for first term of equation we used the product rule?

Homework Equations


https://ibb.co/gHOauJ

The Attempt at a Solution

 
Physics news on Phys.org
Because the divergence operator is applied only to A and then you have multiplication with exponential and psi.
That is, it is ##(\nabla\cdot A)(e^{\lambda}\psi)## , it is not ##\nabla \cdot (Ae^{\lambda}\psi)##
 
Last edited:

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
11
Views
2K