# Did the dominant cosmic structure forming force change over time?

## Hypothesis

During an earlier epoch the universe was filled with hot dense plasma. During this time the dominant structure forming force was electromagnetic. As plasma is prone to self organizing the remnant of this epoch can be seen in the largest scale structures in the universe namely filaments. As the universe cools and condenses however large plasma currents degenerate and gravity becomes the dominant force. There is also room for other fundamental forces to have dominated in even earlier epochs.

Certain cosmic objects appears to have needed more time to form than the age of the universe if gravity alone is the structure forming force.

## Question

Is there an astrophysical theory that holds that different fundamental forces dominated structure formation at different stages in the evolution of the universe?

The electromagnetic force was indeed the dominant force in the early universe in a period up to about $$370,000$$ years after the Big Bang, when the universe had cooled sufficiently to allow neutral helium and hydrogen atoms to exist (an event know as recombination).

After recombination most of the matter in the universe was in the form of neutral atoms and dark matter, neither of which is affected by the electromagnetic force - matter and radiation were effectively decoupled. The cosmic microwave background radiation (CMBR) gives us a snapshot of the universe as it was at recombination. From this point on the dominant long range force in the universe became gravity, which has remained the case ever since.

Any large scale structures that formed in the early universe before recombination would be visible in the CMBR, which has been extensively studied in great detail. I haven't heard of any theory that suggests plasma filaments formed such large scale structures. The existence of galaxy filaments is attributed to the gravitational clustering of dark matter.

• Something about your answer troubles me. During the plasma stage just before recombination, is there a specific affect of EM on the electrons and nuclei other than relatively short range effects? I am guessing that in any large volume, the total electric charge influence outside of the volume would be very small. This would limit the inter-volume affects to likely be smaller than the inter-volume gravitational affects. Do you disagree?
– Buzz
Nov 14 '20 at 16:40
• @Buzz - Just because Debye shielding is acting does not mean the kinetic gas does not care about EM fields. It also does not mean that there are not macroscopic magnetic fields, which would definitely govern particle dynamics. Dec 11 '20 at 12:53
• @honeste_vivere - Thank you for the clarification.
– Buzz
Dec 12 '20 at 16:11