I think I have some alternative explanation for dark energy, but not the education to express it mathematically. Regardless, the basic concept of my idea is this: the deformation of spacetime due to gravity is the driving force behind the expansion of the universe.

Consider the typical analogy of a sheet of elastic material, such as latex. There are two ways of creating a larger surface area on this material, both involve stretching. You can either pull the sheet uniformly in all directions, or apply pressure to one part of the sheet. This behaves in the same way that mass deforms space. The presence of any energy in spacetime creates a deformation which gives rise to the force we know as gravity. This bending of spacetime must create additional space though to account for the curvature, in the same way the surface area of an elastic sheet increases as it's stretched.

This may also have some potential explanation for the strange behavior of gravity in the early stages of the universe, as well as gravity's relative weakness compared to expectation. As the elastic sheet is stretched further it becomes harder to deform - think of a sheet of elastic material pulled taught compared to one hanging loosely. Now consider the idea that gravitational force transfers at the speed of light along with the fact that we're able to peer into the very beginning of the universe with powerful telescopes. This can very easily imply that the driver of the Big Bang and current universal expansion is simply that space is bending as a result of the incredibly dense regions located at the edge of our observable universe. This preserves that space expands uniformly everywhere still as the observable universe is unique at every point in space.

This may be entirely unreadable and a load of shit, regardless I hope it's at least an interesting thought and worth some consideration.