The Early Universe cont There could still be

The Early Universe (cont. ) There could still be signs of the early Universe lying around • the Universe could act like an atom – it would have a ground state – it would have excited states • known as a false vacuum – it could be describable by a solution to quantum mechanics equations • a so called wavefunction of the Universe – transitions could occur between excited states and the ground state • • could be responsible for inflation at the time of strong nuclear force decoupling inflation could rely on the stability of the Universe – imagine a hill with a marble on top • this represents the unified forces – a little push in any direction makes the marble fall downward towards the lowest point • in the process gravitational energy is released • this marks the decoupling of the strong nuclear force from the unified forces – now imagine the Universe is composed of many hills • if one marble falls, not all are required to do so • some localized marbles might stay in their upper states

The Early Universe (cont. ) • this might signify the presence of local regions of unified forces in the midst of the present Universe – these regions of unified forces are known by physicists as cosmic strings • would contain huge amounts of mass (trillions of tons per millimeter) • would not emit radiation • a viable model for dark matter – some evidence might exist for cosmic strings • large scale structure observations indicate some degree of coherence in the thin medium density structures that connect large high density structures • large scale structures typically measure 1016 solar masses and are 30 Mpc across with 1 million galaxies within them The structure of space itself could reflect the nature of the forces • we always speak of space and time – this implies 4 dimensional space – called spacetime • a fifth dimension was introduced to explain the behavior of electromagnetism within spacetime – use same principles of curved spaces in deflection of light by gravity in 4 -d spacetime to describe how electric fields could attract or repel

The Early Universe (cont. ) • The most modern theories of unified forces involve 11 or more dimensions – 1 for time – 10 for space • 7 dimensions would be hidden in loops in normal 3 D space • curved paths due to any force could be interpreted as interactions on one or more loops of hidden spacetime associated with a given force – such a spacetime implies the presence of supermassive particles • could be a source of dark matter – could extend this to ordinary particles such as electrons • normally thought of as point particles • could actually be spheres of compact space 9