A new approach to non-commutative inflation. (English) Zbl 1217.83060
Summary: We propose an inflationary scenario inspired by a recent formulation, in terms of coherent states, of non-commutative quantum field theory. We consider the semiclassical Einstein equations, and exploit the ultraviolet finiteness of the non-commutative propagator to construct the expectation value of the energy-momentum tensor associated with a generic scalar field. It turns out that the latter is always finite and dominated by an effective cosmological constant. By combining this general feature with the intrinsic fuzziness of spacetime, we show that non-commutativity governs the energy density of the early Universe in such a way that the strong energy condition is violated. Thus, there might be a bounce and a subsequent inflationary phase, which does not need any ad hoc scalar field.
MSC:
83F05 | Relativistic cosmology |
83C65 | Methods of noncommutative geometry in general relativity |
83D05 | Relativistic gravitational theories other than Einstein’s, including asymmetric field theories |
81T20 | Quantum field theory on curved space or space-time backgrounds |
83C75 | Space-time singularities, cosmic censorship, etc. |
83C40 | Gravitational energy and conservation laws; groups of motions |
83C05 | Einstein’s equations (general structure, canonical formalism, Cauchy problems) |
83C47 | Methods of quantum field theory in general relativity and gravitational theory |