REVIEW
Adventures in de Sitter space
High Energy Physics - Theory · Submitted 17 May 2002 · 51 references
Pith's verdict: A clean, honest Festschrift survey; the only real soft spot is the topology-changing fragmentation endpoint, which the paper itself hedges in the body even if the abstract is a shade more confident.
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Referee report
The paper
The paper claims
The largest black hole that can fit in de Sitter space is unstable: a perturbation of mode number $n$ can produce $n$ black holes whose evaporation leaves $n$ disconnected de Sitter universes.
The reading
What carries the argument
The load-bearing object is the Nariai solution, a direct product $S^1times S^2$ with both radii equal to $ell/sqrt{3}$, obtained as the $Eto E_{max}=3^{-3/2}$ limit of Schwarzschild-de Sitter. Its instability is analyzed mode by mode: a perturbation proportional to $cos(nx)$ on the $S^1$ becomes superhorizon when the $S^1$ expands by a factor $n$, and the subsequent evolution is matched to $n$ copies of Schwarzschild-de Sitter. The evaporation argument uses the paper's one-loop $s$-wave effective-action analysis and its nonlinear numerical evolution. The review ties this to entropy bounds defined with causal diamonds, $C(p,q)=J^-(q)cap J^+(p)$, which restrict which regions an observer can actually probe.
Extended reading notes
Core claim
The central claim is that the Nariai geometry, the limiting Schwarzschild-de Sitter black hole in which the black-hole and cosmological horizons coincide, is not a stable endpoint. A perturbation with angular mode number $n$ on the $S^1$ factor first oscillates, then grows when the $S^1$ expands past the horizon scale; it seeds $n$ black-hole interiors and $n$ asymptotic de Sitter regions. Semiclassical evaporation then removes the black holes, and the $S^1times S^2$ spatial sections pinch at $n$ points, leaving $n$ separate $S^3$ de Sitter universes. The author presents this as a slow semiclassical process, not a Planck-scale fluctuation, and uses it to argue that small changes in topologically identical initial data can produce an arbitrary number of disconnected components of future infinity.
Load-bearing premise
The fragmentation endpoint assumes that the semiclassical evaporation of the $n$ black holes continues through the final stage, where the two-sphere shrinks to zero size and Planckian curvatures appear; the paper acknowledges that this endpoint is usually assumed rather than calculated.
Original abstract
This is my contribution to the Festschrift honoring Stephen Hawking on his 60th birthday. Twenty-five years ago, Gibbons and Hawking laid out the semi-classical properties of de Sitter space. After a summary of their main results, I discuss some further quantum aspects that have since been understood. The largest de Sitter black hole displays an intriguing pattern of instabilities, which can render the boundary structure arbitrarily complicated. I review entropy bounds specific to de Sitter space and outline a few of the strategies and problems in the search for a full quantum theory of the spacetime.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
This is my contribution to the Festschrift honoring Stephen Hawking on his 60th birthday. Twenty-five years ago, Gibbons and Hawking laid out the semi-classical properties of de Sitter space. After a summary of their main results, I discuss some further quantum aspects that have since been understood. The largest de Sitter black hole displays an intriguing pattern of instabilities, which can render the boundary structure arbitrarily complicated. I review entropy bounds specific to de Sitter space and outline a few of the strategies and problems in the search for a full quantum theory of the spacetime.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | This is my contribution to the Festschrift honoring Stephen Hawking on his 60th birthday. | background 0.79 | 0.21 | 0.01 | asserted 0.98 |
| s1 | Twenty-five years ago, Gibbons and Hawking laid out the semi-classical properties of de Sitter space. | background 1.00 | 0.02 | 0.02 | asserted 1.00 |
| s2 | After a summary of their main results, I discuss some further quantum aspects that have since been understood. | contribution 0.87 | 0.40 | 0.04 | asserted 0.83 |
| s3 | The largest de Sitter black hole displays an intriguing pattern of instabilities, which can render the boundary structure arbitrarily complicated. | result 0.88 | 0.48 | 0.36 | asserted 0.60 |
| s4 | I review entropy bounds specific to de Sitter space and outline a few of the strategies and problems in the search for a full quantum theory of the spacetime. | contribution 0.88 | 0.34 | 0.11 | asserted 0.64 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
References
How the literature uses it
51 arXiv papers cite this in 74 sentences
Papers citing it · 46 sentences without a confident label
Cites it as background 27 papers
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When the static coordinates, together with the natural units, where $ħ= c = G = k_B = 1$ are used, the line element of the de Sitter spacetime may be written as: [ref] [equation] The de Sitter spacetime has the cosmological horizon, where [equation] Unfortunately, the de Sitter metric is singular at the cosmological horizon, and therefore we shall consider, instead of the cosmological horizon itself, a sort of "shrinked horizon", which is a spacelike two-sphere with constant $r$ and $t$ just inside of the cosmological horizon, where $r=r_C$.
Vacuum Energy, Black Holes and the Cosmological Constant · Introduction · 0.83
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The cosmological constant is normally introduced by hand inside the Einstein-Hilbert action in order to reproduce the accelerated expansion of the universe [ref] .
The cosmological constant emerging from a symmetry invariant · Introduction · 0.97
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We start by reminding the following classical GR result: the static and spherically symmetric gravitational field generated by a point mass assuming a vanishing cosmological constant is given by the Schwarzschild geometry [ref] , while allowing for a non-vanishing cosmological constant the generated gravitational field is described by the Schwarzschild-(anti) de Sitter space-time [ref] .
Binary X-ray sources in massive Brans-Dicke gravity · Introduction · 0.93
Discussion
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