What Is the Rh = ct Cosmology?

[Buzz Bloom]

I have been looking at several articles recently about the R_h = ct cosmology, but none of them have explained the meaning of the equation. They just assume than anyone looking at such an article will already know what it means. I guess that (1) h is the Hubble "constant", and (2) c is the speed of light, and (3) t is some kind of time. But R is a mystery. R must be a units like m s, but i can't think of what such a variable might be.

Will someone please explain this?

 

[Chalnoth]

Coasting cosmology. This would be an accurate picture of our universe if the universe was perfectly empty. All objects within such a universe would move at constant velocity.

The "$R_h = ct$" description is because in such a universe, the Hubble radius (given by $R_h = c / H_0$) increases with time as $ct$.

People talk about this universe because it rather coincidentally comes somewhat close to matching observations (it completely fails to describe our universe at very early times, however).

 

[Buzz Bloom]

Hi Chalnoth:

Thank you very much for your post completely answering my question. I also apperciate your not mentioning the dumb mistake I made regarding R_h having units m s.

Regards,
Buzz