Complex sentence: Geoffrey Richard Grimmett (born 20 December 1950) is a mathematician known for his work on the mathematics of random systems arising in probability theory and statistical mechanics, especially percolation theory and the contact process.
Split into simpler sentences: Geoffrey Richard Grimmett (born 20 December 1950) is a mathematician working in probability theory. He is known for his work on the mathematics of random systems arising in probability theory and statistical mechanics, especially percolation theory and the contact process.