In philosophy of mathematics, someone is called a Platonist if they believe a mathematical proof is part of reality, but also that it is not part of the universe, but a parallel "ideal" one.
Some think this idea affects economics and our ideas of time. It is hard to say, since it is so basic in the Western culture. Plato and his student Aristotle had many ideas which are still the most important in this culture. It is hard to say if this one was critical. God's eye view may be more important, especially in politics.
Today, Platonism is mostly considered a philosophy of mathematics but not of science or reality in general. This might under-estimate its effects. But no one calls themselves Platonist other than a few mathematicians today.