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

I Dark energy and expansion of space

  1. Oct 2, 2016 #1
    universe is expanding since the bigbang so therefore space is expanding, but apparently dark energy remains constant, it apparently isn't getting diluted as the universe expands

    is energy being created, specifically the energy in vacuum?
  2. jcsd
  3. Oct 2, 2016 #2


    User Avatar
    Gold Member

    "Space is expanding" is not correct. Google "metric expansion" for a discussion.

    Yes, dark energy is being created as bound systems get farther apart from each other. The density of dark energy remains the same.
  4. Oct 5, 2016 #3
    Hm, do you know of any experimental evidence that dark energy density is constant in time, or is this just an assumption? Specifically, do you have any reason to believe that the average dark energy density is not inversely proportional to the "total volume"; i.e. that the "total dark energy content" is not constant after all?
    Last edited: Oct 5, 2016
  5. Oct 5, 2016 #4


    User Avatar
    Gold Member

    My references are all just other posts (by knowledgeable people) here on this forum. It is not an assumption, it is taken as empirically-based fact but I can't point you to a study saying so. I don't mean to imply that there aren't any, just that I don't have a citation for you.
  6. Oct 5, 2016 #5


    User Avatar
    Science Advisor

    What do you mean by this? Isn't spacetime defined by a manifold with a metric on it? :)
  7. Oct 5, 2016 #6


    User Avatar
    Gold Member

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

Have something to add?
Draft saved Draft deleted

Similar Discussions: Dark energy and expansion of space
  1. Dark Energy (Replies: 6)