This could be the same utility function that I am talking about, but it could also be one of a risk neutral agent with a diminishing marginal utility for money.
Those are intimately-linked concepts, as I understand it:
Quantified utility models simplify the analysis of risky decisions because, under quantified utility, diminishing marginal utility implies “risk aversion”.
Those are intimately-linked concepts, as I understand it:
http://en.wikipedia.org/wiki/Marginal_utility#Revival