Gas of wormholes: a possible ground state of Quantum Gravity

TL;DR

This paper suggests that the ground state of quantum gravity may be a 'gas' of wormholes, implying space-time is best described by a quantum foam structure at the Planck scale.

Contribution

It introduces a variational calculation indicating that quantum fluctuations favor a wormhole gas configuration over flat space, proposing a new model for quantum gravity's ground state.

Findings

Quantum fluctuations favor a wormhole gas ground state.

Space-time can be modeled as a Planck-scale lattice.

The ground state resembles Wheeler's quantum foam.

Abstract

In order to gain insight into the possible Ground State of Quantized Einstein's Gravity, we have derived a variational calculation of the energy of the quantum gravitational field in an open space, as measured by an asymptotic observer living in an asymptotically flat space-time. We find that for Quantum Gravity (QG) it is energetically favourable to perform its quantum fluctuations not upon flat space-time but around a ``gas'' of wormholes of mass m_p, the Planck mass (m_p ~= 10^{19}GeV) and average distance l_p, the Planck length a_p(a_p ~= 10^{-33}cm). As a result, assuming such configuration to be a good approximation to the true Ground State of Quantum Gravity, space-time, the arena of physical reality, turns out to be well described by Wheeler's quantum foam and adequately modeled by a space-time lattice with lattice constant l_p, the Planck lattice.