  In recent years, investigations of gravitational interactions has led us to
discover new facets of the fundamental force. With these discoveries the
general theory of relativity is under greater scrutiny now than it was 100
years ago. Development of a more advanced theory is needed for experimental
tests and extensive predictions of gravitational interactions in local and
cosmological settings. In this work, we present axioms of a novel theory that
describes spacetime as a relativistic viscoelastic continuum; retaining the
properties of the natural ${}^{+}\Lambda$-CDM vacuum. With these axioms, we
provide a foundation for a tensor field theory of Gravitational Strain;
introduced as an advanced formulation of an elastic interpretation of
gravitational interactions. This viscoelastic definition of gravity is a
natural advancement of general relativity to an observable measure of a proper
relativistic gravitational field.
