It is my understanding that there is evidence from the red shift/distance relationship that while the rate of universal expansion was once decreasing (from the Big Bang until about 6-7 billion years ago -BYA for short), at about 6-7 BYA it began increasing. This, as I understand it, is the main evidence for "dark energy." Assuming I'm correct in the above, my questions are the following: 1) did Hubble's original linear relationship between red shift and distance take into account gravitational slowing of the rate of expansion? By this I mean, would a plot of red shift on the y-axis and distance on the x-axis be pulled slightly below a straight line (with negative slope) to reflect such slowing? (I should say that in my imagined plot, I've got 14 BYA at the x origin, and present time at the far right, so the Hubble plot starts high at the left, and hits zero on the y-axis at the right.) In other words, was Hubble's "linear" relationship slightly downward bowed? (Not phrased very precisely, but I hope you understand my question.) 2) At ~ 7BYA, does that plot begin to change from having a gradually decreasing rate of expansion to a gradually increasing rate? (I assume this means the plot around 7 BYA would have an inflection point, and from then on, be bowed upward rather than downward.) I assume the plot is never level and always has a negative slope (i.e., there's a monotonically decreasing red shift as objects get nearer the earth).