How does relativity relate to universe expansion and Einstein's cosmological constant?

[phys lover199]

hi every body

i have a question what is the relation bet relativity and the expansion of the universe




and how einstine formed his cosmological condtant

 

[qraal]

hi every body

i have a question what is the relation bet relativity and the expansion of the universe

The relationship is that general relativity predicts a universe has to be either expanding or contracting. Holding perfectly still is like balancing a pencil on it's point - a slight change and it tips.

and how einstine formed his cosmological condtant

The cosmological constant was added by Einstein in hope of a static Universe solution - the constant would keep the Universe from expanding or contracting, but the balancing act is incredibly difficult.