Expansional Field Theory: Physical Foundations and Unified Derivation of Universal Constants.

Updated version including a dedicated section on Dynamic Isotropy: Expansional Rescaling and the Absence of Preferred Directions and its relation to emergent Lorentz symmetry. Abstract. We present the Expansional Field Theory (EFT), founded on a geometric substrate of cubic tessellation of space that supports a scalar field , referred to as the expansional field, whose local dynamics are Lorentz-compatible. From this structural framework, we derive —in a continuous and non-circular chain— all the fundamental magnitudes of the physical universe: the minimum mass , fine-structure constant , speed of light , Planck constant , expansional rate , gravitational coupling , thermo-structural constant , expansional tension density , and cosmological time . Cosmological time emerges as an intrinsic magnitude of the expansional field itself —a direct manifestation of the activation and propagation rhythm of the substrate cells. It is not introduced as an external parameter or independent variable, but as the internal measure of the expansional field’s unfolding over its geometric substrate. In this sense, the passage of time physically represents the progressive expansion of the expansional field upon the substrate, and its flow defines the evolution of the universe itself. The model also deduces the cell-edge lengths and , the Gravitational Invariant , the gravitational constant , the expression for surface gravity, and finally the structural equivalence between mass and energy, culminating in the structural derivation of Planck’s constant from purely geometric and energetic principles of the field. The EFT demonstrates that the rest energy of matter emerges directly from the expansional field itself, thereby unifying mass, energy, and spatial geometry within a single framework. Furthermore, the model accurately reproduces observed magnitudes without introducing ad hoc parameters (for example, for Earth and Sun, the error is ≤ 0.1 %). This first work focuses on the structural core of the expansional field, where the fundamental constants and their geometric interdependence are established, providing the theoretical foundation for the subsequent cosmological, gravitational, and quantum models.