Schrödinger's time-dependent equation (general)

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Discussion Overview

The discussion revolves around Schrödinger's time-dependent equation and its implications for quantum mechanics, particularly focusing on the Hamiltonian operator and its role in describing the energy states of a system. Participants explore its application to non-relativistic particles and harmonic oscillators, as well as the mathematical underpinnings of the equation.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant describes the Hamiltonian operator as a representation of the total energy of a system, questioning its relation to the wave function and its applicability to non-relativistic particles and harmonic oscillators.
  • Another participant states that the Hamiltonian serves as the "energy operator" and discusses the relationship between eigenstates of the Hamiltonian and energy measurements.
  • A later reply emphasizes that the equation describes how the state varies over time when expressed in terms of position eigenstates, suggesting a need for a deeper understanding of quantum mechanics principles.
  • Further clarification is provided regarding the time evolution of the state vector, noting differences between the Schrödinger and Heisenberg pictures of quantum mechanics.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation of the Hamiltonian and its implications, indicating that multiple competing views remain on the topic. The discussion does not reach a consensus on the specific applications or interpretations of the equation.

Contextual Notes

Some participants acknowledge the mathematical complexity of the topic and suggest that a complete development of quantum mechanics is necessary for full comprehension. There are references to specific texts that may aid in understanding, but no consensus on the best approach is established.

Paradox101
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The Hamiltonian operator in the equation i×h/2π×∂/∂t×ψ=H×ψ(where 'i' is the imaginary no.,'h/2π' is just expanded form of the reduced Planck constant,'∂/∂t' is the partial derivative with respect to time 't' and ψ is the wave function) is,as I recall,H=I+V(i don't know how to get those carets on top of them) implying the "set of possible outcomes when measuring the total energy of a system".What does this mean?Does it relate to state of the system,i.e,the wave function at time t?or can it also be used for a non-relativistic particle(particle not at the speed of light) with a given position or perhaps a harmonic oscillator?
 
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The Hamiltonian ##H=-\frac{\hbar^2}{2m}\frac{\partial^2}{\partial x^2}+V(x)## is the "energy operator" just like ##p=i\hbar\frac{\partial}{\partial x}## is the momentum operator. So, eigenstates of the Hamiltonian are eigenstates of energy, and the average energy of a state is simply ##\langle E\rangle = \langle\psi|H|\psi\rangle##.
 
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Paradox101 said:
What does this mean?Does it relate to state of the system,i.e,the wave function at time t?or can it also be used for a non-relativistic particle(particle not at the speed of light) with a given position or perhaps a harmonic oscillator?

Its simply an equation describing how the state (when expanded in terms of position eigenstates) varies in time

That may be a bit of gibberish right now. To fully understand it you need to see a complete development of QM from first principles.

It likely is more mathematically advanced than you are at present, but the book to have a look at is Ballentine - Quantum Mechabics - A Modern Development:
https://www.amazon.com/dp/9814578584/?tag=pfamazon01-20

In particular have a look at the first 3 chapters. I think its likely you will get the gist even if the mathematical detail is a bit obscure.

Thanks
Bill
 
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More precisely: It's the time evolution of the position-representation components of the state vector, representing a pure state. The time evolution of the state vector itself depends on the picture of time evolution chosen. E.g., in the Heisenberg picture the state vector doesn't change at all (by definition), while in the Schrödinger picture it's evolving with the full Hamiltonian.
 

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