English
The characteristic function can be expressed as a Fourier-type integral against the inner product character: χ_μ(t) = VectorFourier.fourierIntegral probChar μ bilinFormOfRealInner 1 (−t).
Русский
Характеристическая функция выражается через четыреier-интал, как χ_μ(t) = VectorFourier.fourierIntegral probChar μ bilinFormOfRealInner 1 (−t).
LaTeX
$$$$\\chi_{\\mu}(t) = \\mathrm{VectorFourier.fourierIntegral}(probChar, \\mu, bilinFormOfRealInner, 1, -t).$$$$
Lean4
/-- `charFun` is a Fourier integral for the inner product and the character `probChar`. -/
theorem charFun_eq_fourierIntegral (t : E) :
charFun μ t = VectorFourier.fourierIntegral probChar μ bilinFormOfRealInner 1 (-t) := by
simp [charFun_apply, VectorFourier.fourierIntegral_probChar]