“Lorentz-Invariant Measure for Path Integrals in the Future Cone” (2026), by Vladimir Viktorovich Belokurov et al. Mathematics research paper. Original abstract below, unchanged. A free PDF is available.

Lorentz-Invariant Measure for Path Integrals in the Future Cone

Vladimir Viktorovich Belokurov, Vsevolod V. Chistiakov, Klavdiia A. Lursmanashvili et al. · November 3, 2026 · Mathematics

Abstract

We construct a measure on continuous paths in the future cone of two-dimensional space that is invariant under the orthochronous Lorentz group and quasi-invariant under the action of the diffeomorphism group. We use the proposed measure to obtain the fundamental solution of the heat equation. The result agrees with the expression obtained by other methods.

Free PDF DOI: 10.48550/arxiv.2611.04669