Formulas
- Regular icosahedron
- Regular number
- Regular skew polyhedron
- Relation between Schrödinger's equation and the path integral formulation of quantum mechanics
- Relational algebra
- Relative density
- Relative likelihood
- Relativistic Breit–Wigner distribution
- Relativistic angular momentum
- Relativistic quantum mechanics
- Relativistic wave equations
- Renormalization group
- Reo Coordination Language
- Repeating decimal
- Representation theory of the Galilean group