Analytic Continuation

Analytic Continuation is a technique in complex analysis that extends the domain of a given holomorphic function to a larger region. It is fundamental in number-theory and quantum-field-theory for assigning finite values to divergent series and integrals.

Key Concepts

  • Uniqueness: If two analytic functions agree on a set with an accumulation point within their domain, they are identical on the connected component containing that set.
  • Riemann Zeta Function: The classic example where converges only for . Analytic continuation allows evaluation at , yielding .
  • Regularization: A process used in physics to handle infinities, often relying on analytic continuation to extract meaningful physical quantities from divergent expressions.

Applications in Quantum Physics

  • Casimir Effect: The calculation of vacuum energy between plates relies on summing zero-point energies, which diverge. Analytic continuation provides a finite, measurable result.
  • String Theory: Critical dimensions and partition functions often require analytic continuation of the zeta function to ensure consistency.
  • Zeta Function Regularization: A method to define the determinant of operators with infinite eigenvalues by using .

Notable Derivations

  • The result is not a standard sum but the value of the analytically continued zeta function at .
  • This value appears in the Casimir effect and bosonic string theory calculations.
  • For a detailed breakdown of this derivation in the context of quantum physics, see: 12 for Quantum Physics Applications

References