The Big Bang Theory | Theory of a Deadman | music theory | probability theory | theory | Lucky Number Slevin | Theory of relativity | Reynolds number | Mach number | theory of relativity | Social learning theory | serial number | Random number generation | International Standard Book Number | Game Theory (band) | Game Theory | Conspiracy theory | prime number | Personal identification number | number | Music theory | K-theory | AP Music Theory | Two in a Million/You're My Number One | Social Security number | Rikki Don't Lose That Number | Prime number | Premium-rate telephone number | Piaget's theory of cognitive development | Jackass Number Two |
In algebraic number theory, a reflection theorem or Spiegelungssatz (German for reflection theorem – see Spiegel and Satz) is one of a collection of theorems linking the sizes of different ideal class groups (or ray class groups), or the sizes of different isotypic components of a class group.