A Phenomenological Extension of the Cosmological Constant Inspired by Selector-Time Theory: Evidence from Pantheon+ Supernovae

This record contains the revised version (v2.0) of a phenomenological extension of the cosmological constant inspired by the Selector-Time Theory (STT). In this work, the standard assumption of a strictly constant cosmological term is relaxed through the introduction of a structured redshift-dependent formulation Λ(z), based on a bounded transformation z/(1+z). This formulation is motivated by a structural decomposition framework in which effective physical behavior emerges from a dominant component combined with residual corrections. The model is tested against the Pantheon+ Type Ia supernova compilation, providing an integrated probe of the expansion history of the Universe. The results show a consistent improvement over the standard ΛCDM model (Δχ² ≈ -5.7), indicating that structured variation in the cosmological sector may offer a viable extension of the standard cosmological model. This article represents the deterministic stage of the STT cosmological program. A complementary Bayesian validation using MCMC methods is developed in a companion article. This version includes scientific revision, improved methodological clarity, and full bilingual alignment (Portuguese and English). All scripts, figures, and outputs are provided to ensure full reproducibility.