A few notes before the Big Bang

Neil Turok

We came for something, something violent, something extraordinary.

Two possibilities:

1. Time non exist in the beginning.

2. 10 spatial dimensions + time

(BRANE) We have to be almost two branes. When they collide, remained extended. Plasma and matter. All is measured.

Sitter spacetime scale factor and the gravitational wave perturbations a scale-invariant spectrum (|vk/a|2 ∝hH2/k3ij(x) is the three-metric for a maximally symmetric space.

The Penrose diagram of the Sitter spacetime in the flat slicing.

Check out: Quantum Incompleteness of Inflation

Authors: Alice Di Tucci, Job Feldbrugge, Jean-Luc Lehners, Neil Turok

Journal ref: Phys. Rev. D 100, 063517 (2019)

The discussion emphasizes that, even if the inflationary scale is far below the Planck mass, new physics is required to explain the initial quantum state of the universe.


Param Singh

t=0

10-34 star the universe.

Infinite = small universe

Repulsive gravity. Rebounded universe. Big Bounce. Cyclic stages.

Big Bang wasn’t the beginning.


Michio Kaku

All emerge on an instant for nothing (no space, no equations, no time) – perfect Vacuum -Energy transforming in matter.


Andrei Linde

Inflation. Smooth universe in every direction. Massive universe. Is needed the Big Bang? Heavy vacuum and eternal inflation. Multiverse…

Too arbitrary, yep! Swiss cheese model.


Lee Smolin

Everything for nothing. Singularity.

Evolution laws. Ancestor: Black Hole Universe.

Offspring Universe.


Roland Penrose

Expanded universe (no matter, no photons, no clock).


Laura Mersini-Houghton

Universe as a wave. String Theory.

Void in the CMB. Presence of neighboring universes.

Laura Mersini-Houghton

https://arxiv.org/abs/1807.10833

Testing Predictions of the Quantum Landscape Multiverse 3: The Hilltop Inflationary Potential, present the Hilltop model, and the corrections introduced by the entanglement in the quantum landscape multiverse to the slow-rolling inflaton field and to the inflaton potential, showing as anomalies in the CMB spectrum.

Authors: Eleonora Di Valentino, Laura Mersini-Houghton

The quantum landscape multiverse describes the emergence of the universe from a wavefunction on the landscape before inflation, to a present-day classical universe. Other branches of the wavefunction, originating similarly to ours, are entangled with our universe. This quantum entanglement contributes as a second source a correction term in the gravitational potential of the universe, and it gives rise to modifications of the inflation potential and field evolution.