English

Pointwise spinor quantum fields cannot be microcausal nor Poincar\'e covariant

General Relativity and Quantum Cosmology 2025-10-02 v1 High Energy Physics - Theory Mathematical Physics math.MP Quantum Physics

Abstract

We extend and strengthen no-go results on pointwise-defined quantum fields to cover general spinors. We show that the weak continuity of quantum fields rules out equal-time canonical conjugate (anti)commutation relations in globally hyperbolic spacetimes; for quantum fields on Minkowski spacetime, weakly continuous translation covariance enforces the needed continuity and yields the same no-go. We also extend Wightman's no-go theorem to show that the weak continuity of quantum fields rules out fermionic microcausality in C2C^2 Lorentzian spacetimes. We finish by generalising Wizimirski's no-go theorem to show that the existence of a Poincar\'e-invariant vacuum precludes pointwise spinorial covariance on a Minkowski background -- ruling out, in particular, pointwise covariance for Weyl and Dirac fermions, for photons and gravitons -- which further highlights the difficulty of quantising gravity pointwisely.

Keywords

Cite

@article{arxiv.2510.00786,
  title  = {Pointwise spinor quantum fields cannot be microcausal nor Poincar\'e covariant},
  author = {Samuel Fedida},
  journal= {arXiv preprint arXiv:2510.00786},
  year   = {2025}
}

Comments

8 pages

R2 v1 2026-07-01T06:10:22.772Z