Quantum action principle (Feynman's path integration); Consistent observation principle (symmetries and renormalization); Spacetime inflation principle (gravity/gauge or classic/quantum duality, dimensional and holographic evolution of the Universe);
abstract: For a consistent picture of fundamental physics and cosmology, three first principles are proposed as the foundations. That is, quantum variational principle that provides the formalism, consistent observation principle that sets physical constraints and symmetries, and spacetime inflation principle that determines physical contents (particle fields and interactions). Under these three principles, a series of supersymmetric mirror models are constructed to study various phases of the universe at different spacetime dimensions and the dynamics between the phases. In particular, mirror symmetry, as the orientation symmetry of the underlying geometry, plays a critical role in the new framework.