> But the observations actually see the opposite, the increasing acceleration No, the observations are consistent with an increasing expansion rate, i.e. with

> But the observations actually see the opposite, the increasing acceleration No, the observations are consistent with an increasing expansion rate, i.e. with a positive first derivative of the expansion rate, a.k.a. acceleration. How does that derivative change over time? If the second derivative is negative, you have a decreasing acceleration: the expansion rate is accelerating, but less at time T+1 than at time T. In other words, you are getting your derivatives mixed up.