Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How are inflaton particles that drive the early inflation created?

  1. Aug 25, 2013 #1
    Assuming that the early inflation of the universe is driven by the potential energy of some inflaton field(s), the "normal" matter is created only after this rapid inflation has stopped by conversion of the latent energy of the corresponding phase transition to particles.

    Does this mean that the 3 fundamental forces and the corresponding particles summerized in the standard model of particle physics were not yet present during the inflation and even earlier, such that the inflaton particles themself have to be created exclusively by non SM processes?

    What are the assumed processes and interactions that are capable of producing the inflaton particles themself?
     
    Last edited: Aug 25, 2013
  2. jcsd
  3. Aug 26, 2013 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Welcome to PF;
    The inflation period itself, in Big Bang cosmology, forms the first part of the electro-weak epoch. i.e. gravity and the strong force have separated out. i.e. these forces were present during inflation.
     
  4. Aug 27, 2013 #3

    bapowell

    User Avatar
    Science Advisor

    Do you have a reference for this? Have GUT-scale and other SUGRA-based models of inflation been somehow ruled out?
     
  5. Aug 27, 2013 #4
    Looking at this presentation (slide 19), the energy scale at which the inflation period occurs is depicted as having a large uncertainty. Is there any evidence to suggest that it was actually nearer the electroweak scale (the bottom end of the range shown) rather than higher, in BSM land?
     
    Last edited by a moderator: May 6, 2017
  6. Aug 27, 2013 #5

    bapowell

    User Avatar
    Science Advisor

    Right, that's what I'm getting at. The energy scale of inflation is only observable through the presence of tensor perturbations in the CMB generated by primordial gravitational waves. The amplitude of tensors is commonly given in terms of the tensor/scalar ratio: the latest Planck constraints give [itex]r<0.1[/itex] at 95% CL. The slow roll approximation gives
    [tex]V_0^{1/4} \sim \left(\frac{r}{0.7}\right)^{1/4}\times 1.8 \times 10^{16}\, {\rm GeV}[/tex]
    where [itex]V_0[/itex] is the vacuum energy density of inflation when the observed perturbations were generated -- this is the energy scale of inflation. With the Planck bound on [itex]r[/itex], we get [itex]V_0^{1/4} \lesssim 10^{16}\,{\rm GeV}[/itex], well above the electroweak scale.
     
    Last edited by a moderator: May 6, 2017
  7. Aug 27, 2013 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Pretty much any sophomore physics text dealing with the subject has it on it's timeline for the Big Bang as "inflationary epoch".
    This may or may not be what was intended but I'm not going to get more sophisticated than that unless I have to :)

    Not to my knowledge.
    I figured I'd wait before writing a text book ;)

    You seem to be having fun though. Enjoy.
     
  8. Aug 31, 2013 #7
    I started looking in this question a little after the Planck results came out earlier this year (I'm referring to the inflationary timeline stuff)... I remember being a little surprised by the lack of confidence voiced (I'm talking informally) from the physics community.

    Anyway, I think I have some links stashed away from the episode--I'll edit them in if i can. (Then again if you wanted rigorous text-booky material you'll want bapowell or simon, but like I said i'll see what (if) I can find.)


    Speak of the devil: https://www.physicsforums.com/showthread.php?t=707029
     
  9. Sep 4, 2013 #8
    Thanks for these comments, I rather thought too that the inlation energy scale should be at or above the GUT scale.

    @Sheaf thanks for the link to the power point talk, this looks interesting

    @bapowell is there some reference where it is explained how gravitational waves cause tensor perurbations of the CMB background?
     
  10. Sep 4, 2013 #9

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: How are inflaton particles that drive the early inflation created?
Loading...