Hi, Everybody know that eigenfunction of position operator x' is [itex] \delta(x-x') [/itex](adsbygoogle = window.adsbygoogle || []).push({});

But i also knew that integral of square of current state over entire space is 1(probability)

Then, [itex] \int_{-\infty}^{\infty}\delta(x-x')\delta(x-x')^{*} dx [/itex] is 1?

What is conjugate of [itex] \delta(x-x') [/itex]?

And i wandered whether negative energy exists. In classical mechanics, I know potential

energy can have negative sign such as product of electron(negative charge) and voltage.

If electron is at position which potential is larger and kinetic energy of electron, electron

can have negative energy.

Is it vaild in QM?

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# [Q]eigenfunction of position operator and negative energy

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