The phenomenon of redshift in the context of cosmology is primarily associated with the expansion of space itself. It affects electromagnetic waves, such as light, as they propagate through expanding space. However, it's important to note that not all waves experience redshift due to space expansion.
Redshift occurs because as space expands, the wavelength of the light waves stretching along with it also increases. This causes a shift of the light towards longer wavelengths, which is observed as a redshift. It's worth noting that redshift due to space expansion is a result of the changing scale factor of the universe and is distinct from other forms of redshift, such as Doppler redshift.
In the context of particle waves, such as electron waves or other matter waves in quantum mechanics, their behavior is not directly influenced by the expansion of space. These waves are governed by quantum principles and are associated with the properties of the particles themselves, rather than being influenced by the space they propagate through.
While the concept of waves is present in both electromagnetic waves and matter waves, they have different underlying mechanisms and are subject to different physical laws. Electromagnetic waves, including light, are fundamentally different from matter waves associated with particles like electrons.
So, in summary, the redshift observed in light due to the expansion of space is a specific consequence of the nature of electromagnetic waves and the changing scale of the universe. Other types of waves, such as matter waves associated with particles, are not directly affected by the expansion of space in the same way.