Phase Space and two dimensional Hilbert Space

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Discussion Overview

The discussion centers around the differences and similarities between Classical phase space and two-dimensional Hilbert space, exploring their definitions, applications, and underlying principles in the context of physics.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions the main difference between Classical phase space and two-dimensional Hilbert space, suggesting they may be the same.
  • Another participant requests references to support the claims made about Classical phase space and its relation to eigenvalues and eigenvectors.
  • A participant describes Classical phase space as a symplectic space that represents the dynamics of a particle, contrasting it with the quantum description in Hilbert space.
  • It is noted that the interpretation of vectors in Classical phase space involves real coordinates for position and momentum, while in Hilbert space, vectors have complex coordinates representing quantum states.
  • One participant acknowledges potential miscommunication in their earlier description of phase space and expresses gratitude for the clarifications provided by others.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between Classical phase space and Hilbert space, with some asserting clear distinctions while others suggest similarities. The discussion remains unresolved regarding the accuracy of the initial claims about phase space.

Contextual Notes

Participants highlight the need for further reading and clarification on the definitions and applications of phase space and Hilbert space, indicating potential misunderstandings in the initial descriptions.

Gean Martins
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I always had this doubt,but i guess i never asked someone. What's the main difference between the Classical phase space, and the two dimensional Hilbert Space ?
 
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What reading have you got on both things?
 
my brief understanding for each one is :

The Classical phase space allowed me to describe the dynamics of a system by its eigenvalues and eigenvectors, given from a Hamiltonian .

The two dimensional Hilbert Space, its quitely the same thing,but here i work with eigenstates that my system can assume,restricted by rules of this vectorial space ,where my observables are represented by operators acting on eigenstates.

i don't know if i make myself clear,but my question remains : There's no difference between them ?
 
Do you have a reference for this ?
[...]The Classical phase space allowed me to describe the dynamics of a system by its eigenvalues and eigenvectors, given from a Hamiltonian .[...]
 
Actually, i wrote this from my previous knowledge acquired from undergraduate course in physics.
 
I am sorry, you need to do some more reading. We cannot answer questions coming from misunderstandings whose clearing you cannot grasp.
 
Gean Martins said:
i wrote this from my previous knowledge acquired from undergraduate course in physics.

What textbook were you using? Can you give a reference from it that explains where your statement in post #3 comes from?

(And in case it isn't apparent, the reason we are asking is that your description of classical phase space and dynamics doesn't look right; it looks like a description of quantum Hilbert space and dynamics. So it seems like you are confusing the two.)
 
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A 2-dimensional space (but a symplectic space, not a Hilbert space) describes classical linear dynamics of a single particle in 1 dimension. In contrast, a 2-dimensional Hilbert space describes quantum linear dynamics of a single spin degree of freedom. The interpretation of a vector in the two spaces is also quite different: Each 2-dimensional vector in the classical symplectic space has real coordinates and describes position and momentum of a moving particle, while a 2-dimensional vector in the quantum Hilbert space has complex coordinates and is just a representative of a ray describing a point on the Bloch sphere, corresponding to a pure spin 1/2 state of a particle at rest.
 
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I've used basically two books for my readings on Classical Mechanics ,they are : Classical dynamics of particles and systems - Stephen T. Thornton and Jerry B. Marion. ; And Mecânica Analítica - Nivaldo Lemos;

Maybe, i might have expressed badly on my definition of a Phase Space, so i don't want to relate the ideas that I've pass with the books that i used, they are great for advanced introduction on Classical Mechanics. I want to thank you all for the answers, especially A . Neumaier , that's an answer that i was expecting to get . Thank you good sir.

I
 

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