Dynamics of Light String Field and Unified Derivation of Relativistic Effects: Derivation of Lorentz Transformation and Gravitational Field Equations Based on the First Principle Unified Theory of Light Strings

This work establishes a complete first-principle unified theory based on the light string as the only fundamental entity of the universe. From a minimal axiom system without additional assumptions, it rigorously derives:Lorentz transformation, time dilation, length contraction, and the constancy of the speed of lightNewtonian gravity, Poisson equation, and the physical origin of gravitational constant GEinstein field equation and its correspondence to light string field dynamicsMass origin, Higgs mechanism, Planck formula, and mass–energy relationUnification of the four fundamental forcesCosmological constant Λ and Hubble constant H₀This theory unifies special relativity, general relativity, quantum mechanics, gravity, and cosmology in a single self-consistent framework, providing fundamental ontological explanations for space-time, mass, force, and cosmic structure. All results are mathematically closed, experimentally compatible, and free of extra dimensions or free parameters.