In quantum electrodynamics (QED), wave functions are not described as transverse waves, compression waves, fluctuating spherical bulges, or waves that oscillate into non-spatial dimensions or other fields. Instead, wave functions in QED describe the quantum mechanical behavior of particles, specifically electrons and photons, within the framework of quantum field theory.
In QED, particles such as electrons and photons are represented as excitations of quantum fields. These fields pervade all of space and are associated with their respective particles. The behavior of these particles is described by wave functions, which are mathematical functions that encode the probability amplitudes for various outcomes of measurements.
Wave functions in QED are complex-valued functions defined over spacetime. They describe the probability amplitudes for finding a particle at different positions and times. The square of the absolute value of the wave function gives the probability density of finding the particle at a particular location.
It's important to note that wave functions in QED do not have a direct physical interpretation in terms of classical waves or bulges. They are mathematical entities that encode the probabilistic behavior of quantum particles. The interpretation of wave functions and the associated particles in terms of classical wave-like or particle-like behavior emerges from the principles of quantum mechanics and the formalism of QED.