A Measure of de Sitter entropy and eternal inflation

By N. Arkani-Hamed, S. Dubovsky, Alberto Nicolis, E. Trincherini, G. Villadoro. 2007

214 citations recorded by the source corpus.

We show that in any model of non-eternal inflation satisfying the null energy condition, the area of the de Sitter horizon increases by at least one Planck unit in each inflationary e-folding. This observation gives an operational meaning to the finiteness of the entropy S_dS of an inflationary de Sitter space eventually exiting into an asymptotically flat region: the asymptotic observer is never able to measure more than e^(S_dS) independent inflationary modes. This suggests a limitation on the amount of de Sitter space outside the horizon that can be consistently described at the semiclassical level, fitting well with other examples of the breakdown of locality in quantum gravity, such as in black hole evaporation. The bound does not hold in models of inflation that violate the null energy condition, such as ghost inflation. This strengthens the case for the thermodynamical interpretation of the bound as conventional black hole thermodynamics also fails in these models, strongly suggesting that these theories are incompatible with basic gravitational principles.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/0cfebcf9ac4fc609dbacc003f24b609ab122fa06

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Citations in the corpus

The cosmological Higgstory of the vacuum instability (2015, background): “This generalises at the quantum level the bound on the duration of inflation found in [71], and determines the universality of such a bound under the number of fields involved, higher derivative corrections, number of space time dimensions and slow roll parameters.”
On loops in inflation (2009, background): “This provides additional insight on how to interpret de Sitter space within quantum gravity [20, 19].”
Semiclassical relations and IR effects in de Sitter and slow-roll space-times (2010, background): “[17, 18] suggested a breakdown of a different origin due to small spacing between nice slices.”
Solving the simplest theory of quantum gravity (2012, unknown): “, [8], for a related discussion).”
Looking for a bulk point (2015, background): “This is also sometimes explained by saying that high energy scattering will typically make a black hole that evaporates into a large number of particles, so that producing just two particles in the final state would be highly unlikely [31, 32].”
The phase transition to eternal inflation (2008, background): “In particular there are reasons to suspect that the semiclassical description of eternal inflation, with its infinite creation of volume may be misleading (see for example [30]) or even that eternal inflation itself may be censored in a fundamental theory [33]; if this is the case the effective theo”
The effective theory of quintessence: the w < 1 side unveiled (2008, background): “In particular, the violation of the null energy condition may be problematic in the context of black hole thermodynamics [35].”
Effective field theory of cosmological perturbations (2013, methodology): “It was applied to inflation in [6, 7] and then more systematically developed by Cheung et al in [8].”
Replica wormholes and the black hole interior (2019, background): “A starting point could be the “centaur” geometry [85] or possibly the large number of states produced by quantum field theory evolution over many e-folds, which was previously considered in the context of the de Sitter entropy in [86, 87].”
Quantum compositeness of gravity: black holes, AdS and inflation (2013, background): “Some interesting previous attempts, within the standard semi-classical treatment, to set a bound on the number of e-foldings based on assigning finite entropy to de Sitter can be found in [25–27].”
Covariant Loop Quantum Gravity: An Elementary Introduction to Quantum Gravity and Spinfoam Theory (2014, background): “A second source for the prejudice is the consideration that local observables require infinite precision and this can only be achieved with infinitely long or infinitely extended measurements: in a region of size L it does not make sense to discuss time evolution with a time resolution better than δ”
Inflation, Cosmic Perturbations and Non-Gaussianities (2013, background): “The global structure of spacetime is not accessible by an observer in a black hole [86].”
Simple de Sitter solutions (2007, background): “Some progress toward a general framework for duals of metastable de Sitter space have appear in [53].”
Analyticity and the holographic S-matrix (2011, background): “(3) Recently, progress [21, 20, 22, 23, 24, 25, 26] has been made understanding general properties 1 See [14, 15] for nice and relevant discussions. of CFTs using only the conformal block decomposition, unitarity, and crossing symmetry.”
The Effective Field Theory of Inflation (2007, background): “Moreover all single field models are unified in a common framework and this allows us to draw general conclusions which are independent of the specific realization, as done in [12, 31] for example.”