How Can I Verify a Canonical Transformation Using the Poisson Bracket?

In summary, the conversation discusses verifying the equation q_bar=ln(q^-1*sin(p)) and p_bar=q*cot(p) using a canonical transformation. The poisson bracket is defined and it is stated that a canonical transformation preserves the poisson bracket of p and q. The conversation also mentions other ways to show the equation, such as using a generation function.
  • #1
skrtic
15
0

Homework Statement



Verify that

q_bar=ln(q^-1*sin(p))

p_bar=q*cot(p)


* represents muliplication

sorry i don't know how to use the programming to make it look better



2. The attempt at a solution

my problem is that i really have no clue what is going on. I have read the section, reread the section, then looked on online just to try and find an example. I am much more of a visual learner so reading doesn't help all the time.

I guess I'm looking for some guidance of what/how to do. and not even this proble, but just an example or process.
 
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  • #2
a canonical transformation preserves the poission bracket

i.e the possion bracket of p and q: {q,p}_(p,q) = 1

thus if {q_bar, p_bar}_(p,q) = 1, then it is a canonical transformation.

(there are more ways to show it, like if there exists a generation function.. but I like the poission bracket the most, it is easy to remember)

The poission bracket is defined as
[tex]\left\lbrace f,g \right\rbrace _{(q,p)} = \dfrac{\partial f}{\partial q}\dfrac{\partial g}{\partial p} -\dfrac{\partial f}{\partial p}\dfrac{\partial g}{\partial q} [/tex]
 

1. What is a Canonical Transformation?

A Canonical Transformation is a mathematical transformation that preserves the Hamiltonian equations of motion and the Poisson bracket structure of a system. It is used to simplify the equations of motion in classical mechanics and to transform coordinates in quantum mechanics.

2. Why are Canonical Transformations important in physics?

Canonical Transformations are important in physics because they allow us to find new sets of coordinates that simplify the equations of motion and reveal underlying symmetries in a system. They also help us to connect different physical theories and relate seemingly different systems.

3. How is a Canonical Transformation different from a general coordinate transformation?

A Canonical Transformation is a special type of coordinate transformation that preserves the Hamiltonian equations of motion and the Poisson bracket structure. In contrast, a general coordinate transformation does not necessarily preserve these properties and may change the form of the equations of motion and the symplectic structure.

4. What are the two types of Canonical Transformations?

The two types of Canonical Transformations are point transformations and generating function transformations. Point transformations involve a direct transformation of coordinates, while generating function transformations involve finding a generating function that can be used to generate the new coordinates through a set of equations.

5. How are Canonical Transformations related to conservation laws?

Canonical Transformations are related to conservation laws through Noether's theorem. This theorem states that for every continuous symmetry in a physical system, there is a corresponding conservation law. Since Canonical Transformations preserve the equations of motion, they also preserve the underlying symmetries and corresponding conservation laws of a system.

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