Gravitational radiation on transition?

[Tio Barnabe]

Is it possible for a transition between two atomic states to proceed by emission of gravitational, rather than electromagnetic, radiation?

 

[hilbert2]

There have been some hypothetical models of hydrogen-like quantum systems, where instead of a proton and an electron, two Planck-scale microscopic black holes orbit each other with the gravity acting as a binding force. Actually, one of my teachers wrote a paper about this when I was an undergraduate (but I can't find it now for some reason).

EDIT: Oh, here it is: http://iopscience.iop.org/article/10.1088/0264-9381/18/3/302

 

[Tio Barnabe]

But is it possible to have a truly hydrogen atom, and for some reason, the system gravitationally loses/gain some energy and this causes the electron to change its state?

Maybe I should be clear:

A particle in general has its state changed when there's a change in the energy, correct? (One of the rules of QM here.)

Now QM doesn't tell us what kind of process the particle should be subjected to in order to say, lose its energy. This means that in principle say, the electron in the hydrogen atom, can get its state changed if the system (the hydrogen atom) gravitationally loses energy.

 

[hilbert2]

If you add a static gravitational potential proportional to ##\frac{1}{r}## in the hydrogen atom Hamiltonian, corresponding to the gravitational attraction between electron and proton, it will cause a very very tiny shift in the energy levels. If you're thinking about something like a hydrogen atom with the electron on a 2p orbital moving to 1s (ground) state by emitting a graviton with an energy corresponding to the difference of 2p and 1s states, then that's definitely not going to happen - and the probability for it can't even be calculated as far as I know (because there's no working quantum field theory for gravity).

 

[Tio Barnabe]

If you add a static gravitational potential proportional to ##\frac{1}{r}## in the hydrogen atom Hamiltonian, corresponding to the gravitational attraction between electron and proton

What if the whole atom, that is, the electron and the proton, is falling down on a gravitational field? (And we consider the interaction between the atom and the gravitational field, instead of the attraction between the electron and the proton.)

 

[Lord Jestocost]

What if the whole atom, that is, the electron and the proton, is falling down on a gravitational field? (And we consider the interaction between the atom and the gravitational field, instead of the attraction between the electron and the proton.)

Are you thinking about the quantum states of neutral particles in a gravitational field as, for example, is dealt with in Measurement of quantum states of neutrons in the Earth's gravitational ...

 

[Tio Barnabe]

Oh cool, I will take a look at it