>>16716304
Please refrain from calling it dark energy. It offends people who actually know general relativity. It means the geometry of space is (locally) hyperbolic. Go ahead and draw a hyperboloid of one sheet. Is it a compact surface? Same argument for the vanishing cosmological constant: Minkowski space is non-compact.
>>16716308
There are thousands of papers on testing Poincare invariance violations. People sometimes say Lorentz invariance because the Poincare group is sometimes called the inhomogeneous Lorentz group.