4
votes
1answer
37 views

Does expanding space cost energy?

Does the cosmic inflation reduce the energy density proportionally to the volume, or does the inflation "cost" energy? Is space itself "something"?
0
votes
1answer
748 views

How did the inflaton field “add” energy to the universe?

How did inflation add energy to the universe? What mechanism did this occur by? In other words, where did that energy come from? Was it due to the quantum fluctuation (or that scalar field rolling ...
8
votes
3answers
1k views

photons in expanding space: how is energy conserved?

If a photon (wave package) redshifts (streches) traveling in our expanding universe, is it's energy reduced? If so, where does it go?