Is Symmetry Required for Determining the Hamiltonian?

In summary, a Hamiltonian is a mathematical function that represents the total energy of a physical system and is used to describe its dynamics over time. It is crucial in understanding the behavior of a system and making accurate predictions. The Hamiltonian is determined by identifying relevant energy terms and combining them into a single function, taking into account the kinetic and potential energy of each component. The key principles behind determining the Hamiltonian are the conservation of energy and the principle of least action. In quantum mechanics, the Hamiltonian is used to describe the total energy and behavior of a quantum system, playing a fundamental role in calculating important quantities such as energy levels.
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My book writes a 5-step recipe for detemining the hamiltonian, which I have attached. However I see a problem with arriving at the last result. Doesn't it only follow if the matrix M is a symmetric matrix - i.e. the transpose of it is equal to itself.
 

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  • #2
I am assuming the tilde above an object implies taking a transpose. If that is the case, then M is indeed a symmetric matrix. One can see this by looking at the Lagrangian. Since the Lagrangian is a number, we can take a transpose of L and we'll get back the same number, i.e. [itex]L^T=L[/itex], this will rewrite the Lagrangian in terms of [itex]M^T[/itex]. But since these are equal, we must have [itex]M^T=M[/itex]
 

FAQ: Is Symmetry Required for Determining the Hamiltonian?

What is a Hamiltonian?

A Hamiltonian is a mathematical function that represents the total energy of a physical system. It is used to describe the dynamics of a system over time.

What is the importance of determining the Hamiltonian?

Determining the Hamiltonian is crucial in understanding the behavior of a physical system. It allows us to predict how the system will evolve over time and make accurate calculations of its properties.

How is the Hamiltonian determined?

The Hamiltonian is determined by identifying all the relevant energy terms in the system and combining them into a single function. This involves taking into account the kinetic and potential energy of each component of the system.

What are the key principles behind determining the Hamiltonian?

The key principles behind determining the Hamiltonian are the conservation of energy and the principle of least action. The Hamiltonian must accurately reflect the total energy of the system and the dynamics of the system must follow the path that minimizes the action.

How does the Hamiltonian relate to quantum mechanics?

In quantum mechanics, the Hamiltonian is used to describe the total energy of a quantum system and its behavior over time. It is a fundamental concept in quantum mechanics and is used to calculate important quantities such as the energy levels of an atom or molecule.

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