kolmogorov used measure theory develop axiomatic framework probability theory publication book widely considered birth modern probability theory theories probability stochastic processes became parts mathematics ref name bingham ref name cramer publication kolmogorov 's book fundamental work probability theory stochastic processes done khinchin kolmogorov well mathematicians joseph doob william feller maurice fr chet paul l vy wolfgang doeblin harald cram r ref name bingham ref name cramer decades later cram r referred heroic period mathematical probability
Formal science Mathematics Pure mathematics Probability theory Stochastic process