# De Broglie Wavelength

1. Jan 5, 2007

### Harmony

1. Since velocity is relative to the reference frame, would the de Broglie Wavelength varies from one observer to another?

2. What will happen if the matter is stationary?

2. Jan 5, 2007

### cesiumfrog

These are incomplete answers, but maybe they'll inspire better ones:

1. Sure, but QM and relativity don't tend to sit well together.
2. Nothing, there is still a random thermal velocity.

3. Jan 6, 2007

### marlon

If one would apply the principles of special relativity onto QM, YES !

Stationary with respect to what frame ?

marlon

4. Jan 6, 2007

### Truth Finder

Harmony,
Special relativity has been totally implied into QM (Previosity: Schroedinger)
through Dirac's and KELIN-GORDON, for fermions and bosons respectively.
Of course, Cesium, this was the case before Dirac's. But, there are still two problems in QM and also in QFT; a. can't deal with Gravity and b. didn't contain GR effects ...... There are differences as introduced to me by Amr Morsi.
Got you ..... Morsi
Marlon, this is a very good question, especially when Dirac's, or even Schroedinger (non-relativistic of course), can be applied to dynamic non-conservative fields.

Thanks to permit me to add another question: What is the meaning of De Broglie Wavelength in the view of the newer probability concept of Probability Density Function?

Schwartz Vandslire.

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Either to do it correctly as required, or to leave it as required.

5. Jan 6, 2007

### marlon

The de broglie wavelength is a property of a single particle (corresponding to a single energy eigenstate) while a density function describes a group of particles (ie the corresponding wavefunction is a superposition (or tensor product like a Fock space) of single particle wavefunctions which in themselves can contain multiple energy eigenstates if they are non stationary and thus exhibit a spread in their momentum or "deBroglie wavefunction"). So, no straightforeward relation, IMO.

marlon

Last edited: Jan 6, 2007
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