We know that the energy of a massless photon is measured by it's frequency. As a graviton is massless as well it must travell at the speed of light.

Here are my questions:
Can a graviton have different energy levels and what property causes this, frequency?
If a graviton can have different frequencies then how are they produced?
If the graviton can only have a ground energy state is the in- or decrease of a gravitational field then produced only by an in- or decrease of particles.

Is the graviton produced by mass itself or is it a the counter product to mass created by spacetime?
If the last one is the case where does the vacuum borrows its energie from?

Hope you can answer them all.

See ya!

Originally posted by Paulus
We know that the energy of a massless photon is measured by it's frequency. As a graviton is massless as well it must travell at the speed of light.

Here are my questions:
Can a graviton have different energy levels and what property causes this, frequency?

a graviton, like a photon, can have any energy. it does not have energy levels. energy levels are for bound particles, and virtual particles are perturbative approximations to free particles.
If a graviton can have different frequencies then how are they produced?
energy is the source of gravitons.
If the graviton can only have a ground energy state is the in- or decrease of a gravitational field then produced only by an in- or decrease of particles.
umm... the graviton is a fundamental particle, so it does not have excited states.
Is the graviton produced by mass itself or is it a the counter product to mass created by spacetime?
the graviton is produced my energy.
If the last one is the case where does the vacuum borrows its energie from?
the vacuum does not borrow energy. there may quantum fluctuations due to uncertainties, but the vacuum is the ground state of all fields. it has no free energy by definition.

Thanks Lethe for your quick reply!

I like to follow up your answers because there are still some things I don't understand.

You said that in comparison to bound particles virtual particles like the graviton can have any energy. First of all, can I replace bound-and virtual particle for fermions and bosons?

If the graviton can contain different energy levels it must have Planck scale steps.
So if a massless boson like the graviton can have any energy then how is this level altered? By frequency like the Photon?

If energy itself creates gravitons, then how does this work?
For instance if the mass/energy of a star like the sun generates a gravitational field then this field can also be seen as energy and therefore produces gravitons as well? Or can gravitons only be created by the energy of fermions?

What do you mean by your statement about the vacuum and no FREE energy?
Can the groud state of all fields be understood as the lowest energy level posible?
If this is the case does this implicate that further stretching (expanding) of the universe would not be possible because the vacuum has reached his lowest energy state?

See ya!

Originally posted by Paulus
Thanks Lethe for your quick reply!

I like to follow up your answers because there are still some things I don't understand.

You said that in comparison to bound particles virtual particles like the graviton can have any energy. First of all, can I replace bound-and virtual particle for fermions and bosons?
not sure what you re asking here. in general, massless particles are extremely hard to find in bound states, since they always travel at the speed of light. therefore you wouldn t find a graviton with energy levels.


If the graviton can contain different energy levels it must have Planck scale steps.
So if a massless boson like the graviton can have any energy then how is this level altered? By frequency like the Photon?
yes, like the photon, the energy of the graviton is proportional to its frequency. i will not call these energy levels, since they are not discrete.

If energy itself creates gravitons, then how does this work?
For instance if the mass/energy of a star like the sun generates a gravitational field then this field can also be seen as energy and therefore produces gravitons as well? Or can gravitons only be created by the energy of fermions?
yes, the energy of the sun creates gravitons, which themselves have energy, which can couple to more gravitons. it is this self-interacting behaviour which makes the gravitational field equations nonlinear, and so hard to solve.

What do you mean by your statement about the vacuum and no FREE energy?
Can the groud state of all fields be understood as the lowest energy level posible?
If this is the case does this implicate that further stretching (expanding) of the universe would not be possible because the vacuum has reached his lowest energy state?
See ya!
yes, the vacuum is the lowest energy level. expansion of the universe does not affect the vacuum energy (the vacuum is lorentz invariant), although it does affect the energy of any fields that are occupied above the vacuum level. this is why the cosmic microwave background radiation, which is just the light left over from shortly after the big bang, is so cold today: 2.73 K.