Polymer inflation

Abstract

We consider the semi-classical dynamics of a free massive scalar field in a homogeneous and isotropic cosmological spacetime. The scalar field is quantized using the polymer quantization method assuming that it is described by a gaussian coherent state. For quadratic potentials, the semi-classical equations of motion yield a universe that has an early "polymer inflation" phase which is generic and almost exactly de Sitter, followed by a epoch of slow-roll inflation. We compute polymer corrections to the slow roll formalism, and discuss the probability of inflation in this model using a physical Hamiltonian arising from time gauge fixing. We also show how in this model, it is possible to obtain a significant amount of slow-roll inflation from sub-Planckain initial data, hence circumventing some of the criticisms of standard scenarios. These results show the extent to which a quantum gravity motivated quantization method affects early universe dynamics.

Minisuperspace models as infrared contributions

“…In this form, the scalar model resembles the 3-dimensional version proposed in [16,17] and further evaluated in [18,19,20,21]. The quantum Hamiltonian…”

Quantum Groups and Polymer Quantum Mechanics

“…For other approaches see also [17]. Despite the rich literature, the general issue remains still completely open, and part of the focus is shifting on the so-called polymer quantization (PQ) [18,19] (that is a slightly simplified quantization inspired by LQG, that is reliable and heavily used [20][21][22][23][24][25][26]) and to its application to finite degrees of freedom systems, polymer quantum mechanics (PQM) [27][28][29]. PQ is based on the polymer representation of the Weyl-Heisenberg (WH) algebra, which is a non-regular representation, inequivalent to the standard Schrödinger or Fock-Bargmann representations [30].…”

Natural inflation from polymer quantization

“…Polymer quantized matter has been studied by several authors [15][16][17][18][19][20][21][22][23][24][25]. The polymer quantization of the free scalar field in an isotropic and homogenous setting was studied in [17], while the minimally coupled scalar field was studied in [23]. The effective semiclassical dynamics detailed in [23] indicates that polymer quantized scalar fields with quadratic potentials generically result in an early time "polymer" inflation phase followed by a slow roll inflation phase.…”