Spectral Zeta Function & Casimir Energy

The spectral zeta function ζ_A(s) = Σ λ_n^(-s) encodes eigenvalue spectra. Analytic continuation to s=-1/2 yields zero-point energy — the mathematical heart of the Casimir effect, connecting quantum vacuum fluctuations to spectral geometry.

Spectrum

ζ_A(s) = Σ λ_n^(-s)
ζ_A(s):
ζ_A(-½) (vac.E):
Weyl counting:
Spectral gap: