Einstein gravity as a low-energy effective theory: Comparison with weak and strong interactions

Abstract

Einstein`s theory which correctly describes gravity at long distances (low energies) is first compared with Fermi`s theory, which describes weak interactions at low energies. Analogous to strong interactions at high energies being described by the the gauge invariant finite theory of quantum chromodynamics (QCD), gravity at high energies would be described by an asymptotically free-scale invariant theory. Then just as an effective theory of pions, describing low energy strong interactions, emerges from QCD at low energies, Einstein`s theory would be the low energy effective counterpart of this gauge inavriant high energy theory, ironically arising from the scale invariance being broken by quantum fluctuations. Analogies between QCD and scale invariant gravity are discussed and the cosmological constant probelm is also considered in this context.