About the basics of Poisson bracket

Click For Summary
SUMMARY

The discussion centers on the fundamentals of Poisson brackets within the context of a 2n-manifold M, utilizing a closed non-degenerate differential 2-form w. The Poisson bracket is defined as {f, g} = w^ij ∂_i f ∂_j g, where [w^ij] is the inverse of [w_ij]. Key properties established include the well-defined nature of the Poisson bracket across coordinate patches, its antisymmetry, and the Jacobi identity. Participants emphasize the necessity of understanding transformation rules and smooth functions on manifolds to effectively engage with Poisson brackets.

PREREQUISITES
  • Understanding of 2n-manifolds and their properties
  • Familiarity with closed non-degenerate differential forms
  • Knowledge of smooth functions on manifolds
  • Basic concepts of differential geometry and transformation rules
NEXT STEPS
  • Study the properties of Poisson brackets in detail
  • Learn about transformation rules for smooth functions on manifolds
  • Explore references on differential geometry, particularly on differentiable manifolds
  • Investigate the Jacobi identity and its implications in symplectic geometry
USEFUL FOR

Mathematicians, physicists, and students of differential geometry seeking to deepen their understanding of Poisson brackets and their applications in manifold theory.

sarason
Messages
2
Reaction score
0
Dear all,
Please help me to solve the following problems
about Poisson brackets.
Let M be a 2n-manifold and w is a closed non-degenerate di®eren-
tial 2-form. (Locally we write w = w_ij dx^i ^ dx^j with [w_ij ] being a
non-degenerate anti-symmetric real matrix-valued local function on M)
Let f, g be two smooth functions on M. Define the Poisson bracket
{f, g} as follows: locally,
{f, g} = w^ij \partial_i f \partial_j g
where [w^ij ] is the inverse of [w_ij ].
SHOW that
1) The Poisson bracket is well-defined, i.e., on the intersection of two
coordinate patches, the two definitions, one written in each local co-
ordinate system, actually always agree.
2) {f, g} = -{g, f} and
{f, gh} = {f, g}h + g{f, h}
for any three smooth functions f, g, h.
3) {f, {g, h}} + {g, {h, f}} + {h, {f, g}} = 0
for any three smooth functions f, g, h.

Thank you very much for taking time to consider these problems.

Sarason
 
Physics news on Phys.org
Erm, the answer is to "just do it".

calculate {f,g} on the overlap of two elements in the atlas and use the transformation rules for f and g (it's a smooth function) to show they are equal.

2 and 3, it now suffices to work locally, so do so.

it's not pleasant but that's the way it works I'm afraid.
 
Thanks for your reply. Would you please cite some
references so that I may consult the transformation rules
or the information related to my questions.

Sarason
 
Eh? any book on differential geometry or differential manifolds, or even differentiable manifolds will tell you what it means for a function to be smooth on the manifold. If you've not seen this then trying to do poisson brackets is a little adventurous.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
3
Views
9K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 69 ·
3
Replies
69
Views
9K