what s the osc illating theory of universe?

the oscilaating theory of the universe is the theory on the universe expanding. The gravitational pull of all the galaxies plus whatever the other matter existed in the universe would be great enough to slow down that expansion or even reverse it.

Can you please rephrase this to something I can understand clearly, thanks

Sure, let me rephrase that for you. The oscillating theory of the universe suggests that the expansion of the universe is not a one-way process. Instead, it suggests that the universe goes through cycles of expansion and contraction, like a cosmic "breathing" motion. According to this theory, the gravitational pull of matter in the universe can eventually slow down or reverse the expansion, causing the universe to eventually collapse in on itself. This collapse would then lead to a new cycle of expansion, and the process would repeat indefinitely.