Phase Space and two dimensional Hilbert Space

Click For Summary
SUMMARY

The discussion clarifies the distinction between Classical phase space and two-dimensional Hilbert Space. Classical phase space describes the dynamics of a system using eigenvalues and eigenvectors derived from a Hamiltonian, while two-dimensional Hilbert Space focuses on eigenstates constrained by the rules of vector space, with observables represented by operators. A 2-dimensional classical symplectic space represents position and momentum with real coordinates, whereas a 2-dimensional quantum Hilbert space represents a pure spin 1/2 state with complex coordinates. Key references include "Classical Dynamics of Particles and Systems" by Stephen T. Thornton and Jerry B. Marion, and "Mecânica Analítica" by Nivaldo Lemos.

PREREQUISITES
  • Understanding of Hamiltonian mechanics
  • Familiarity with eigenvalues and eigenvectors
  • Basic knowledge of quantum mechanics and Hilbert spaces
  • Concept of symplectic geometry in classical mechanics
NEXT STEPS
  • Study Hamiltonian mechanics in "Classical Dynamics of Particles and Systems"
  • Explore the concept of symplectic spaces in classical mechanics
  • Learn about quantum mechanics and the role of Hilbert spaces
  • Investigate the Bloch sphere representation of quantum states
USEFUL FOR

Students and professionals in physics, particularly those studying classical mechanics and quantum mechanics, as well as anyone interested in the mathematical foundations of these theories.

Gean Martins
Messages
6
Reaction score
0
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 ?
 
Physics news on Phys.org
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.)
 
  • Like
Likes   Reactions: Gean Martins
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.
 
Last edited:
  • Like
Likes   Reactions: Gean Martins
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
 

Similar threads

  • · Replies 61 ·
3
Replies
61
Views
6K
  • · Replies 16 ·
Replies
16
Views
929
  • · Replies 29 ·
Replies
29
Views
2K
  • · Replies 15 ·
Replies
15
Views
928
  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 55 ·
2
Replies
55
Views
5K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K