Pressure of space/quantum field

[Joshcitylife]

I had a question today as a part of my studies which was 1) If space is ever expanding what is the pressure on the creating space (universe) upon creation and 2) at what rate might you assume the quantum field is also being created and is it being affected by this pressure of creation. This is of course all theoretical and asking for what may lead you to create equations with principal. 
 

Personally I sometime like to think as the universe ever expands and brings in reality its also very similar to a computer game in which a player travels through areas of a map waiting for it to load upon entering. 

Edited May 19 by Joshcitylife

[Mordred]

Use the equation of state for a scalar field. The FLRW metric version is a good starting point.

https://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology)

We already have equations to describe vacuum fluctuations with a pressure term see link. Under GR the stress energy momentum tensor has the pressure terms. This will correspond to how pressure is handled under QFT 

 

[Baoba04]

If space is expanding, from what I remember from some space documentaries, at the beginning of the universe, during the Big Bang, there was super high pressure and temperature. But that was then; now the pressure is pretty low because the universe is expanding and that matter that was compressed is now dispersed. It's kinda like inflating a balloon - at first, it's hard because the pressure inside is high, but then it gets easier and easier.

Quantum fields are even more abstract. But from what I've heard, these quantum fields also stretch with the universe. It's not like they are created anew, but rather as the universe expands, these fields stretch along with it. As for the pressure, I think that pressure at the moment of the universe's creation had an impact on these fields, but not so much now. They already exist and don't change much, unless some major cosmic event happens.

   😀

 

Edited June 5 by Baoba04

[Mordred]

18 hours ago, Baoba04 said:

If space is expanding, from what I remember from some space documentaries, at the beginning of the universe, during the Big Bang, there was super high pressure and temperature. But that was then; now the pressure is pretty low because the universe is expanding and that matter that was compressed is now dispersed. It's kinda like inflating a balloon - at first, it's hard because the pressure inside is high, but then it gets easier and easier.

Quantum fields are even more abstract. But from what I've heard, these quantum fields also stretch with the universe. It's not like they are created anew, but rather as the universe expands, these fields stretch along with it. As for the pressure, I think that pressure at the moment of the universe's creation had an impact on these fields, but not so much now. They already exist and don't change much, unless some major cosmic event happens.

   😀

 

That description above isn't too bad you have the basic idea. Lets expand on it the BB at \(10^{-43}\) s was in a hot, dense state. Now the FLRW metric uses those equations of state above, which are thermodynamic relations between the kinetic energy  and pressure terms of the multi-particle field. Matter has no pressure term as it doesn't have sufficient momentum to generate pressure. However relativistic particles do have the momentum terms. ie photons and neutrinos. 

 The FLRW metric treats expansion as an ideal fluid with adiabatic and isentropic expansion. The Cosmological principle tells us this state is  homogeneous and isotropic.   as the universe expands then accordingly the temperature and  pressure decrease as a result. In point of detail the inverse of the scale factor will give you the CMB blackbody temperature at that value of "a"=scale factor. The equations of state in the above link give the different momentum to pressure relations for radiation, Lambda and matter.

 

[Phi for All]

2 hours ago, allenallure said:

Hello,

Theoretical inquiry explores the pressure on the expanding universe upon creation and the rate of quantum field creation. The analogy to a computer game loading areas prompts reflection on the dynamic nature of reality.

Thank you

!

Moderator Note

We prefer that you respond on your own, without using AI generated language. The above makes little sense as a scientific response to what's been written. "Inquiry explores the pressure on the universe"?! This is a discussion forum for people.