Giorgio Parisi (born August 4, 1948) is an Italian theoretical physicist. He is best known for his works concerning statistical mechanics, quantum field theory and various aspects of physics, mathematics and philosophy of science.Giorgio Parisi's research focused mainly on disordered systems, in particular on spin glass theory. He suggested a crucial concept in spin glass theory, known as Parisi functional. Kardar–Parisi–Zhang equation, describing a behavior of a one-dimensional fluctuating string, is named after Parisi. In 2011,he was awarded the Max Planck Medal for his achievements in theoretical physics.