Sampling instant probability density function (PDF) The key point to notice in Figure 7 is that, even though it is highly probable that the bit will be sampled in the vicinity of the center of the UI, ...

In fact, for Gaussian random jitter probability density functions (PDFs), there theoretically is no limit to how much deviation there might be between the proper and actual time of a clock edge.

Probability density function is a statistical expression defining the likelihood of a series of outcomes for a continuous variable, such as a stock or ETF return.