Punctuated eternal inflation via AdS/CFT

TL;DR

This work embeds inflationary cosmology within a holographic AdS/CFT framework by treating expanding de Sitter bubbles as domain walls inside Schwarzschild–AdS spacetimes. A Semiclassical Consistency Hypothesis ties de Sitter entropy to the finite microstate content of black-hole ensembles, excluding time-symmetric tunneling and enforcing a time-asymmetric, punctuated eternal-inflation picture encoded in a single unitary CFT. By mapping bubble states to CFT data and exploiting boundary-compact holography, the authors derive a timelike, ergodic measure that regularizes the cosmological measure problem and naturally explains late-time acceleration without unphysical bulk tunneling. The framework also provides a mechanism to mitigate paradoxes such as Boltzmann brains, the coincidence problem, and the youngness/oldness paradox, with the arrow of time emerging from spontaneous CPT-symmetry breaking in a CPT-invariant theory. Overall, punctuated eternal inflation in AdS/CFT suggests a concrete, unitary, holographic route to cosmology with testable implications for initial conditions and the landscape of vacua.

Abstract

The work is an attempt to model a scenario of inflation in the framework of Anti de Sit- ter/Conformal Field theory (AdS/CFT) duality, a potentially complete nonperturbative description of quantum gravity via string theory. We look at bubble geometries with de Sitter interiors within an ambient Schwarzschild anti-de Sitter black hole spacetime and obtain a characterization for the states in the dual CFT on boundary of the asymptotic AdS which code the expanding dS bubble. These can then in turn be used to specify initial conditions for cosmology. Our scenario naturally interprets the entropy of de Sitter space as a (logarithm of) subspace of states of the black hole microstates. Consistency checks are performed and a number of implications regarding cosmology are discussed including how the key problems or paradoxes of conventional eternal inflation are overcome.

Figures (8)

• Figure 1: The potential landscape showing the dS metastable and AdS stable vacua. The arrows indicate the time evolution of a possible worldline.
• Figure 2: A Time symmetric bubble trajectory: The left diagram is dS spacetime and the right diagram is SAdS spacetime. The blue curve is the bubble trajectory. The domain wall geometry is made up of the region to the left side of the blue curve in the dS spacetime diagram and to the right side of the blue curve of the AdS spacetime diagram.
• Figure 3: Time asymmetric trajectory : The interior dS region is shown on the left, and the exterior SAdS region is shown on the right. The domain wall geometry is made up of the regions to the left of the blue curve in the dS diagram and to the right of the SAdS diagram joined across the bubble wall (blue curve).
• Figure 4: Penrose diagrams after taking into account perturbations. The left diagram shows the bubble trajectory in dS spacetime. The region to the right of the bubble wall is excised. Eventually any given worldline tunnels back into an AdS region, leading to a big crunch. The diagram on the right shows the trajectory through AdS spacetime. The region to the left of the wall is excised. Perturbations lead to a Cauchy horizon with a null singularity meeting the bubble wall at infinity.
• Figure 5: Punctuated Eternal Inflation: Starting with empty AdS space, dual to the vacuum state of the CFT, a light-like shell, shown by the blue line, collapses into a black hole. A bubble with dS interior, shown by the red curve, appears out of the spacelike singularity. The left side of the red line i.e. the bubble wall is a piece of dS space. This sequence repeats, following the quasiperiodic Poincare recurrences in the dual gauge theory.