Are quantum harmonic oscillators and radiation modes equal?

[Suekdccia]

Are quantum harmonic oscillators, vacuum fluctuations and radiation modes the same?
Is vacuum energy caused by vacuum quantum fluctuations?

 

[azntoon]

No, these are not the same. Quantum harmonic oscillators are systems of particles that vibrate in a regular pattern due to an external force. Vacuum fluctuations are small, quantum fluctuations in fields that occur when the fields are in their lowest energy state (the vacuum). Radiation modes are patterns of electromagnetic radiation, or waves of light, that have specific frequencies and directions. Vacuum energy is related to vacuum fluctuations. It is believed that the energy of the vacuum arises from the quantum fluctuations of matter and fields in space.