Interpretation of the Gravitational Effects of Dark Matter by a Dynamical Weyl Field within General Relativity

This paper investigates whether, during the post-recombination epoch, the gravitational effects attributed to cold dark matter in ΛCDM can be reproduced by an independent dynamical Weyl field , without the need to assume particle dark matter. The hypothesis is formulated within general relativity with a pseudo-Riemannian metric and a Levi-Civita connection. The Weyl field is understood as an independent dynamical degree of freedom, not as the Weyl curvature tensor . Its gravitational effect is described through its contribution to the effective energy-momentum tensor. The paper introduces no new experimental data and leaves open the question of the origin of the corresponding initial conditions before recombination. Observational information from the epoch of last scattering is therefore treated as a constraint on the initial data rather than as a result of the post-recombination dynamics of the proposed model.