Poisson brackets commutator vs. quantum commtation relation

In summary, there are various ways to "quantize" a classical system, depending on what properties you want the resulting quantum system to have. In general, there is no unique way to do this, and in most cases, the resulting quantum mechanical systems are not completely unique, but instead depend on arbitrary constants. The most well-known of these is the so-called "Planck's constant of the universe," which sets the scale of quantum dynamics in the universe.
  • #1
exponent137
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If we have Poisson bracket for two dynamical variables u and v, we can write as it is known ...

This is for classical mechanics. If we write commutation relation, for instance, for location and momentum, we obtain Heisenberg uncertainty relation.

But, what is a pedagogical transfer from Poisson bracket to quantum mechanics. Because formulae are very different, Classical one has partial derivations, quantum one has only multiplication of matrices.

What is transfer to quantum mechanics, or in the opposite direction?

One example of this question:
http://physics.stackexchange.com/qu...tion-between-poisson-brackets-and-commutators
But; i think, that it can be answered more clearly.
 
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  • #3
exponent137 said:
If we have Poisson bracket for two dynamical variables u and v, we can write as it is known ...

This is for classical mechanics. If we write commutation relation, for instance, for location and momentum, we obtain Heisenberg uncertainty relation.

But, what is a pedagogical transfer from Poisson bracket to quantum mechanics. Because formulae are very different, Classical one has partial derivations, quantum one has only multiplication of matrices.

What is transfer to quantum mechanics, or in the opposite direction?
[...]

There's no pedagogical transfer. It's only the axiomatic Dirac quantization (PB/DB --> 1/ihbar x commutator) scheme (shown by Groenewold and van Hove to be severely limited) which is standard textbook material then the further contributions of Weyl, Wigner and Moyal which are only presented in advanced texts (they form the basis for the so-called deformation quantization). The link you gave contains more detailed answers. In the Schrödinger picture of QM, commutators also contain differential operators, quite similarly to the classical PB.
 
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  • #4
One can go a surprisingly long way by simply taking the (classical) dynamical Lie algebra (expressed in terms of Poisson brackets), and re-expressing it by quantum commutators (possibly inserting factors of ##\hbar## to make the dimensions correct). The ambiguities Dex mentioned above, where quadratic and higher products of operators are involved, can often be resolved in practical cases by to simply symmetrizing them. (Indeed this is necessary to obtain a satisfactory Hermitian quantum operator corresponding to the LRL vector in the H-atom problem.) In other cases, one must deform the Lie algebra to obtain a satisfactory quantum version.
 
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What is the difference between Poisson brackets commutator and quantum commutation relation?

The Poisson brackets commutator is a mathematical tool used in classical mechanics to describe how the variables of a system change with respect to each other. It involves the use of Poisson brackets, which are defined as the anti-commutators of the position and momentum variables. On the other hand, quantum commutation relation is a fundamental concept in quantum mechanics that describes the non-commutativity of operators representing physical observables. It involves the use of commutators, which are defined as the difference between the product of two operators and the product of the same operators in the reverse order.

How do Poisson brackets commutator and quantum commutation relation relate to each other?

Poisson brackets commutator and quantum commutation relation are both mathematical tools used to describe the behavior of physical systems. However, they differ in their approach and application. While Poisson brackets commutator is used in classical mechanics to describe the behavior of macroscopic systems, quantum commutation relation is used in quantum mechanics to describe the behavior of microscopic systems.

Are Poisson brackets commutator and quantum commutation relation interchangeable?

No, Poisson brackets commutator and quantum commutation relation are not interchangeable. They are two distinct mathematical tools that are used in different areas of physics. While they both involve the use of commutators, they have different definitions and applications.

What is the significance of Poisson brackets commutator and quantum commutation relation in physics?

Poisson brackets commutator and quantum commutation relation are both important tools in physics as they help us understand the behavior of physical systems. They are used to calculate the uncertainty in measuring certain physical quantities and to describe the evolution of a system over time.

Can Poisson brackets commutator and quantum commutation relation be used together?

Yes, Poisson brackets commutator and quantum commutation relation can be used together in certain cases. For example, when dealing with classical systems with finite degrees of freedom, the Poisson brackets commutator can be used to derive the quantum commutation relation. Additionally, both tools can be used to study the behavior of systems with both classical and quantum characteristics, such as in the field of quantum chaos.

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