Question

The vacuum state is the state with the minimum energy, which implies no excitations, which is the same as a state with no particles. The electric field in empty space has an energy density larger than in a vacuum state with no electric fields generated by nearby electrically charged particles, right? Question: If a field has a value different than zero in some region of space, will its state in that region still be a vacuum? And such a field which has a value larger than for the vacuum (not just the value of the field, but the energy density too), is not the same as an excited field? so it is not necessarily associated with real particles of that field?

Answer 1

In quantum mechanics, the vacuum state has no excitations or particles. A non-zero field in a region of space does not qualify as a vacuum state.

An excited field can have a larger value than the vacuum and its associated energy density, but it is not necessarily associated with real particles of that field.

Step-by-step explanation:

In quantum mechanics, the vacuum state refers to the state of minimum energy, where there are no excitations or particles present.

However, if a field has a non-zero value in a region of space, its state in that region is not considered a vacuum state. This is because the presence of a non-zero field indicates the existence of energy in that region.

An electric field in empty space can have an energy density larger than in a vacuum state with no electric fields generated by nearby charged particles.

This is because the energy density of a field is related to the magnitude of the field, and the presence of charged particles can contribute to the overall field and energy density.

A field with a value larger than the vacuum value, both in terms of field magnitude and energy density, is considered an excited field.

However, it is important to note that an excited field is not necessarily associated with the presence of real particles of that field. Excitations can arise due to various factors such as interactions or disturbances in the field.