Starobinsky R^2 inflation model
E732409
The Starobinsky R² inflation model is a pioneering cosmological model of the early universe in which inflation is driven by a modification of general relativity that adds a term proportional to the square of the Ricci scalar to the gravitational action.
All labels observed (7)
How this entity was disambiguated
This entity first appeared as the object of triple T8396966 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Starobinsky R^2 inflation model Context triple: [Alexei Starobinsky, theoryDeveloped, Starobinsky R^2 inflation model]
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A.
ekpyrotic universe model
The ekpyrotic universe model is a cosmological theory proposing that the universe originated from the collision of higher-dimensional branes, offering an alternative to the standard inflationary Big Bang scenario.
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B.
inflationary universe theory
Inflationary universe theory is a cosmological model proposing that the early universe underwent an extremely rapid exponential expansion, explaining its large-scale uniformity and structure.
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C.
chaotic inflation
Chaotic inflation is a cosmological model proposed by Andrei Linde in which the early universe undergoes rapid exponential expansion driven by randomly distributed scalar fields in a high-energy chaotic initial state.
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D.
FLRW cosmological models
FLRW cosmological models are a family of solutions to Einstein’s field equations that describe a homogeneous and isotropic expanding or contracting universe, forming the standard framework for modern cosmology.
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E.
Affleck–Dine baryogenesis scenarios
Affleck–Dine baryogenesis scenarios are theoretical models in cosmology and particle physics that explain the universe’s matter–antimatter asymmetry via the dynamics of scalar fields carrying baryon number in the early universe.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Starobinsky R^2 inflation model Target entity description: The Starobinsky R² inflation model is a pioneering cosmological model of the early universe in which inflation is driven by a modification of general relativity that adds a term proportional to the square of the Ricci scalar to the gravitational action.
-
A.
ekpyrotic universe model
The ekpyrotic universe model is a cosmological theory proposing that the universe originated from the collision of higher-dimensional branes, offering an alternative to the standard inflationary Big Bang scenario.
-
B.
inflationary universe theory
Inflationary universe theory is a cosmological model proposing that the early universe underwent an extremely rapid exponential expansion, explaining its large-scale uniformity and structure.
-
C.
chaotic inflation
Chaotic inflation is a cosmological model proposed by Andrei Linde in which the early universe undergoes rapid exponential expansion driven by randomly distributed scalar fields in a high-energy chaotic initial state.
-
D.
FLRW cosmological models
FLRW cosmological models are a family of solutions to Einstein’s field equations that describe a homogeneous and isotropic expanding or contracting universe, forming the standard framework for modern cosmology.
-
E.
Affleck–Dine baryogenesis scenarios
Affleck–Dine baryogenesis scenarios are theoretical models in cosmology and particle physics that explain the universe’s matter–antimatter asymmetry via the dynamics of scalar fields carrying baryon number in the early universe.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
cosmological inflation model
ⓘ
early universe model ⓘ modified gravity theory ⓘ |
| addresses |
flatness problem
ⓘ
horizon problem ⓘ monopole problem ⓘ |
| addsTerm | R^2 term in the gravitational action ⓘ |
| alsoKnownAs |
R^2 inflation
ⓘ
linked to:
Starobinsky R^2 inflation model
Starobinsky inflation ⓘ
linked to:
Starobinsky R^2 inflation model
|
| assumes |
Friedmann–Lemaître–Robertson–Walker metric
ⓘ
linked to:
FLRW cosmological models
spatially homogeneous and isotropic universe ⓘ |
| basedOnTheory | general relativity ⓘ |
| belongsToClass | f(R) gravity models ⓘ |
| canBeRewrittenAs | Einstein gravity plus scalar field (Einstein frame) ⓘ |
| compatibleWith |
Planck satellite data
ⓘ
cosmic microwave background observations ⓘ |
| drives | cosmic inflation ⓘ |
| EinsteinFrameContains | scalaron field ⓘ |
| energyScale | inflation scale around 10^13 GeV (order of magnitude) ⓘ |
| framework | metric formulation of gravity ⓘ |
| hasLagrangianDensity | L ∝ R + α R^2 (in the Jordan frame) ⓘ |
| hasNumberOfEfolds | N ≈ 50–60 ⓘ |
| hasParameter | α (coefficient of the R^2 term) ⓘ |
| hasPotentialShape | plateau-like potential in the Einstein frame ⓘ |
| implies | reheating after inflation ⓘ |
| inflationDrivenBy | higher-derivative curvature term ⓘ |
| inflatonIdentifiedAs | scalaron ⓘ |
| influenced |
development of f(R) gravity
ⓘ
plateau inflation models ⓘ |
| introducedBy | Alexei Starobinsky ⓘ |
| introducedIn | 1980 ⓘ |
| is | one of the earliest concrete inflationary models ⓘ |
| isExampleOf | single-field slow-roll inflation ⓘ |
| leadsTo | graceful exit from inflation via R^2 term decay ⓘ |
| modifies | Einstein–Hilbert action ⓘ |
| namedAfter | Alexei Starobinsky ⓘ |
| notableFor | geometric origin of the inflaton degree of freedom ⓘ |
| oftenComparedWith |
Higgs inflation
ⓘ
chaotic inflation models ⓘ |
| originalPublication | A. A. Starobinsky, Physics Letters B 91 (1980) 99–102 ⓘ |
| predicts |
Gaussian primordial perturbations (to leading order)
ⓘ
nearly scale-invariant spectrum of scalar perturbations ⓘ quasi–de Sitter expansion in the early universe ⓘ small tensor-to-scalar ratio ⓘ |
| predictsScalarSpectralIndex | n_s ≈ 1 − 2/N ⓘ |
| predictsTensorToScalarRatio | r ≈ 0.003 (for N ≈ 60 e-folds) ⓘ |
| requires | positive coefficient of the R^2 term for stability ⓘ |
| usesQuantity | Ricci scalar ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Starobinsky R^2 inflation model Description of subject: The Starobinsky R² inflation model is a pioneering cosmological model of the early universe in which inflation is driven by a modification of general relativity that adds a term proportional to the square of the Ricci scalar to the gravitational action.
Referenced by (10)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Starobinsky R^2 inflation model
linked to: Starobinsky R^2 inflation model
linked to: Starobinsky R^2 inflation model
subject linked to:
Starobinsky
linked to: Starobinsky R^2 inflation model
subject linked to:
Starobinsky
linked to: Starobinsky R^2 inflation model
subject linked to:
Starobinsky
linked to: Starobinsky R^2 inflation model
subject linked to:
Starobinsky
linked to: Starobinsky R^2 inflation model
subject linked to:
Starobinsky
linked to: Starobinsky R^2 inflation model
linked to: Starobinsky R^2 inflation model