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Character Fourier Spectra of Circular Units and Twisted Bernoulli Class Components

General Mathematics 2026-07-29 v1

Abstract

Let χ\chi be a primitive odd Dirichlet character of conductor ff. For the universal projector polynomials PmP_m introduced in arXiv:2607.23177, defined by mPm(X)Ym=log(1X(1eY))\sum_m P_m(X)Y^m = -\log(1-X(1-e^{-Y})), we evaluate the character Fourier spectrum at ht=ζft/(ζft1)h_t = \zeta_f^t/(\zeta_f^t-1): for every odd mm, tχˉ(t)Pm(ht)=τ(χˉ)Bm,χ/(mm!)\sum_t \bar\chi(t)P_m(h_t) = \tau(\bar\chi)B_{m,\chi}/(m\,m!). After reduction at any prime above pfp \nmid f, the case m=pjm = p-j identifies this spectrum, including its exact nonzero scalar, with the divided generalized Bernoulli value attached to χωj\chi\omega^{-j}; the spectral-zero and Bernoulli-zero criteria therefore agree over every residue field, with no splitting hypothesis on the coefficient field. We connect the identity with the local Kummer spectrum of the circular unit 1ζfζp1-\zeta_f\zeta_p and carry the programme through in the first non-real case: for the two primitive quartic characters modulo 5 and primes p<500p < 500, p1(mod20)p \equiv 1 \pmod{20}, exactly eleven zero lines occur. On each line an integral character projection of 1ζ5ζp1-\zeta_5\zeta_p is everywhere locally unramified, a finite split-prime Artin computation proves it is not a global pp-th power, and the character-wise Main Conjecture shows the radical generates the complete order-pp Hilbert class component. Six of the eleven components occur at classically regular primes. At p=61p = 61 the two conjugate characters contribute on different indices. A deterministic integer-arithmetic program (ancillary file) verifies the enumeration, the divided digits, and every certificate.

Keywords

Cite

@article{arxiv.2607.27503,
  title  = {Character Fourier Spectra of Circular Units and Twisted Bernoulli Class Components},
  author = {Peter Chocian},
  journal= {arXiv preprint arXiv:2607.27503},
  year   = {2026}
}

Comments

13 pages. Deterministic integer-arithmetic verification program included as ancillary file. Companion to arXiv:2607.23177