Question

I was thinking about what things would look like in a hyperspherical universe. How would galaxies look as they got closer to the other side of that hypersphere? It seems like if a galaxy were on the other side of that hypersphere, light from that galaxy would come from every direction, and it's image would be smear across the entire sky.

So then I was thinking what if the size of the universe was small enough that the light that forms the CMB traveled from locations closer to the other side of the universe than this side. That light would also be smeared, and so be more uniform than we might expect if we thought we lived in a flat universe.

And this would then have an impact on how fast inflation would have to happen in order to account for that uniformity.

I can't be the first one to think of this, but I've never come across an article that's addressed this.

So first question: Does this idea track? Second: Has anyone come across a reference that explores this idea?

Answer 1

In a hyperspherical universe, galaxies would change shape as they approached the other side of the hypersphere. This aligns with the concept of inflation, which suggests a rapid expansion that smoothed out the wrinkles in the universe and resulted in a uniform CMBR.

Step-by-step explanation:

In a hyperspherical universe, the shape of galaxies would change as they got closer to the other side of the hypersphere. Due to the curvature of the universe, light from a galaxy on the other side would be smeared across the entire sky, appearing to come from every direction. If the size of the universe was small enough, the light that forms the Cosmic Microwave Background Radiation (CMBR) would also be smeared, resulting in a more uniform distribution than expected in a flat universe.

This idea aligns with the concept of inflation, which suggests that shortly after the Big Bang, the universe experienced a rapid expansion that stretched the wrinkles in the universe nearly flat, resulting in an extremely smooth CMBR. This inflationary scenario is incorporated into most cosmological theories to explain the uniformity of the CMBR. While there may not be specific articles addressing this exact idea, the concept of inflation and its impact on the CMBR is widely discussed in scientific literature.