All Questions
Tagged with non-locality action
5
questions
3
votes
2
answers
709
views
Effective action as a generating functional and its derivative expansion
On page 381 of Peskin and Schroeder, equation (11.90) reads
$$ \frac{\delta^2 \Gamma}{\delta \phi_{cl}(x)\delta \phi_{cl}(y)} = iD^{-1}(x,y).\tag{11.90}$$
I am having a bit of trouble interpreting ...
- 857
7
votes
2
answers
411
views
Is there a deep reason why action comes from a local lagrangian?
In both classical and quantum physics Lagrangians play a very important role. In classical physics, paths that extremize the action $S$ are the solutions of the Euler-Lagrange equations, and the ...
- 1,290
1
vote
1
answer
125
views
Formulating a symplectic integrator for a non-local Hamiltonian
I recently asked two questions, Q. [1] and Q. [2], regarding reformulating non-local Lagrangians as Hamiltonians.
In these questions, the Hamiltonian is formulated as an integral because of it's non-...
- 411
1
vote
2
answers
552
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An inconsistency in Hamiltonian formulation for non-local Lagrangian: what am I doing wrong?
This question is based on a previous question I asked, Q. [1]
In this question, I proposed an example of a non-local Lagrangian (functional), I'm revisiting it here:
$$\mathbb{L}=\frac{1}{2}\int^t_0 ...
- 411
5
votes
1
answer
569
views
Legendre transform for non-local Lagrangians, or Hamiltonian of non-local Lagrangian and their properties
This is sort of a multi-part question, mostly dealing with how to treat non-local Hamiltonians and how the corresponding properties of Hamiltonians work in a non-local framework. I proposed an example ...
- 411