Rational Homotopy Theory

High Quality Content by WIKIPEDIA articles! In mathematics, rational homotopy theory is the study of the rational homotopy type of a space, which means roughly that one ignores all torsion in the homotopy groups. It was started by Dennis Sullivan (1977) and Daniel Quillen (1969).Rational homotopy types of simply connected spaces can be identified with certain algebraic objects called minimal Sullivan algebras, which are commutative differential graded algebras over the rational numbers satisfying certain conditions.The standard textbook on rational homotopy theory is (Felix, Halperin & Thomas 2001).