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1 vote
1 answer
318 views

On the Hamiltonian vector fields of classical Hamiltonian mechanics

Notation: I denote phase space as the symplectic manifold $(M,\omega)$, in which $\omega=\sum_i\mathrm dp_i\wedge\mathrm dq_i$ in canonical coordinates. In definitions of Hamiltonian vector fields I ...
Charlie's user avatar
  • 6,963
6 votes
3 answers
2k views

Paths in phase space can never intersect, but why can't they merge?

Page 272 of No-Nonsense Classical Mechanics sketches why paths in phase space can never intersect: Problem: It seems to me this reasoning only implies that paths can never "strictly" ...
George's user avatar
  • 337
1 vote
2 answers
333 views

Analogues to Hamilton's equations in Infinitesimal Canonical Transformations

This is from chapter 4 of David Tong's notes on Classical Dynamics (Hamiltonian Formalism). Let's say you make an infinitesimal canonical transformation (with $\alpha$ as the infinitesimal parameter) ...
Tachyon209's user avatar
1 vote
0 answers
65 views

Quantum mechanics in phase space - what are coordinate components?

I'm trying to understand the answer provided by Qmechanic to this question: What's the intuitive reason that phase space flow is incompressible in Classical Mechanics but compressible in Quantum ...
fred's user avatar
  • 123
5 votes
1 answer
756 views

Liouville's volume theorem in differential forms language

I will cast my question mostly in words. I usually find Liouville's volume theorem cast in two forms: Easy way (without differential forms language): Phase space volume remains preserved under ...
Sashwat Tanay's user avatar
8 votes
1 answer
702 views

Can any symplectomorphism (1 Definition of canonical transformation) be represented by the flow of a vectorfield?

For this question I will use the definition that a canonical transformation is a map $T(q,p)$ from the phase space onto itself, which leaves the symplectic 2-form invariant (which is the definition of ...
Quantumwhisp's user avatar
  • 6,763
3 votes
1 answer
71 views

Two first integrals of an hamiltonian field $X_{H}$ are independent $\det \left[ \frac{\partial F_{i}}{\partial p_{k}} \right] \neq 0$

I want to understand how it is established if two first integrals of an hamiltonian field $X_{H}$ are independent. One hypothesis is: Considering two first integrals $F(q^i,p_k)$ $$\det \left[ \...
Stefano Barone's user avatar
11 votes
2 answers
1k views

Does Hamilton Mechanics give a general phase-space conserving flux?

Hamiltonian dynamics fulfil the Liouville's theorem, which means that one can imagine the flux of a phase space volume under a Hamiltonian theory like the flux of an ideal fluid, which doesn't change ...
Peter's user avatar
  • 175