Bianchi II and VII$_{h=0}$ Models Revisited Via The Euclidean-Signature Semi Classical Method

TL;DR

This paper applies a novel semi-classical method to Bianchi cosmological models with matter and electromagnetic fields, revealing new solutions and excited states that enhance understanding of quantum gravity effects without Wick rotation.

Contribution

It introduces a modified Euclidean-signature semi-classical approach to Bianchi models, uncovering new solutions and excited states, and demonstrates its utility in quantum gravity research.

Findings

Found new solutions to Wheeler DeWitt equations in Bianchi models with matter.

Discovered unique 'excited' states differing from previous models.

Showed the method's effectiveness without requiring Wick rotation.

Abstract

We apply in a novel fashion a modified semi-classical method to the Bianchi II and VII$_{h=0}$ models when a cosmological constant, aligned electromagnetic field and stiff matter are present. Additionally we study the non-commutative quantum Bianchi II models when an aligned electromagnetic field is included. Through the use of the Euclidean-signature semi classical method we find a plethora of new solutions to these model's corresponding Lorentzian signature Wheeler DeWitt equations which we can interpret qualitatively. These new solutions for the aforementioned models involving matter sources reveal some potentially interesting effects that should be chronicled as possible phenomena that a toy model of quantum gravity can induce on the evolution of a quantum universe. Furthermore we find 'excited' states which behave differently from the 'excited' states of the Bianchi IX and Taub models that were previously uncovered using this method. By comparing and contrasting the 'excited' states given by these models we help facilitate a better understating of what constitutes an 'excited' state solution of the Wheeler Dewitt equation. Our results further show the utility of the Euclidean-signature semi classical method for tackling Lorentzian signature problems without having to invoke a Wick rotation. This feature of not needing to apply a Wick rotation makes this method potentially very useful for tackling a variety of problems in bosonic relativistic field theory and quantum gravity.