Hermitian Operators and Non-Orthogonal Bases: Exploring Infinite Spaces

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SUMMARY

This discussion focuses on Hermitian operators acting on infinite-dimensional spaces, specifically using the basis {1, x, x², x³, ...}. It highlights that traditional properties of Hermitian operators, such as eigenvectors spanning the space, may not hold in infinite dimensions. The matrix representation of a self-adjoint operator remains equal to its conjugate transpose when using an orthonormal basis, but the basis discussed here is not orthonormal, raising questions about the applicability of these rules in infinite spaces.

PREREQUISITES
  • Understanding of Hermitian operators in linear algebra
  • Knowledge of infinite-dimensional vector spaces
  • Familiarity with self-adjoint operators
  • Concept of orthonormal bases in functional analysis
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Mathematicians, physicists, and students studying quantum mechanics or functional analysis, particularly those interested in the properties of Hermitian operators in infinite-dimensional spaces.

LCSphysicist
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It is not necessary.
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The basis he is talking about: {1,x,x²,x³,...}
I don't know how to answer this question, the only difference i can see between this hermitians and the others we normally see, it is that X is acting on an infinite space, and, since one of the rules involving Hermitian fell into decline in the infinity space (e.g Eigenvectors span the space),i am not sure if another rules changes in the infinity space too..
 
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The matrix of a self-adjoint operator with respect to an orthonormal basis is equal to its conjugate transpose. Your basis is not orthonormal.
 
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Likes   Reactions: Abhishek11235, Delta2, LCSphysicist and 3 others
Infrared said:
The matrix of a self-adjoint operator with respect to an orthonormal basis is equal to its conjugate transpose. Your basis is not orthonormal.
Forgot this detail, thank you.
 

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