Explicit reciprocity laws

Quadratic reciprocity law was conjectured by Euler and Legendre, and proved by Gauss. Gauss made first generalizations of this relation to higher fields and derived cubic and biquadratic reciprocity laws. Eisenstein and Kummer proved similar relations for extension Q(ζp, √n a) partially. Hilbert identified the power residue symbol by norm residue symbol, the symbol of which he noticed the analogy to residue of a differential of an algebraic function field. He derived the properties of the norm residue symbol and proved the most explicit form of reciprocity relation in Q(ζp, √n a). He asked the most general form of explicit reciprocity laws as 9th question at his lecture in Paris 1900. Witt and Schmid solved this question for algebraic function fields. Hasse and Artin proved that the reciprocity law for algebraic number fields is equal to the product of the Hilbert symbol at certain primes. However, these symbols were not easy to calculate, and before Shafarevich, who gave explicit way to calculate the symbols, only some partial cases are treated. Shafarevich’s method later improved by Vostokov and Br¨ukner, solving the 9th problem of Hilbert. In this thesis, we prove the reciprocity relation for algebraic function fields as wel as for algebraic function fields, and provide the explicit formulas to calculate the norm residue symbols.