A Briefing on the Ekpyrotic/Cyclic Universe

Justin Khoury (Columbia Univ.)

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A Briefing on the Ekpyrotic/Cyclic Universe

Justin Khoury (Columbia Univ.)

Astrophysics · Submitted 27 Jan 2004

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim This is a short overview of the ekpyrotic/cyclic model of the universe, an alternative to the standard big bang inflationary paradigm.

how it is stated · asserted 0.94 read the record →

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What the abstract itself states, as probabilities: claims first 0.02 · states limitation 0.14 · human participants 0.02 · controlled comparison 0.10 · randomized assignment 0.01 · states quantitative result 0.02 · compares with prior results 0.16 · mentions code or data availability 0.02.

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This is a short overview of the ekpyrotic/cyclic model of the universe, an alternative to the standard big bang inflationary paradigm.

background contribution method result interpretation main claim

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#	sentence	role	the authors' own work	states the main conclusion	strength
s0	This is a short overview of the ekpyrotic/cyclic model of the universe, an alternative to the standard big bang inflationary paradigm.	contribution 0.51	0.09	0.13	asserted 0.94

What kind of paper the classifier reports this is: review 1.00 · evidence from literature 0.63.

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The paper

Original abstract

This is a short overview of the ekpyrotic/cyclic model of the universe, an alternative to the standard big bang inflationary paradigm.

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References

Forward citations

Cited by 9 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

The shape of non-Gaussianities
astro-ph 2004-05 accept novelty 8.0 of 10

Primordial non-Gaussianity comes in two nearly orthogonal momentum-space shapes, equilateral and squeezed, so constraints on one model do not transfer to another by simple equilateral normalization.
The Pseudo-Conformal Universe: Scale Invariance from Spontaneous Breaking of Conformal Symmetry
hep-th 2011-06 conditional novelty 7.0 of 10

A conformal field theory with a time-dependent expectation value that breaks so(4,2) to so(4,1) generates a scale invariant spectrum of perturbations in a slowly contracting, nearly flat universe, without inflation.
Starting the Universe: Stable Violation of the Null Energy Condition and Non-standard Cosmologies
hep-th 2006-06 accept novelty 7.0 of 10

A ghost-condensate effective theory can violate the null energy condition stably, provided the Hubble rate grows no faster than about H squared, enabling non-standard cosmologies such as w below -1 and a bounce.
DBI Realizations of the Pseudo-Conformal Universe and Galilean Genesis Scenarios
hep-th 2012-09 accept novelty 6.0 of 10

The pseudo-conformal symmetry-breaking pattern can be realized by a DBI probe brane in an AdS bulk, giving subluminal perturbations and a geometric, shift-protected weight-zero field with a scale-invariant spectrum.
Non-linear Realizations of Conformal Symmetry and Effective Field Theory for the Pseudo-Conformal Universe
hep-th 2012-02 accept novelty 6.0 of 10

Applying the coset construction to the symmetry breaking so(4,2) to so(4,1) yields the most general effective action for the Goldstone mode and weight-zero matter of the pseudo-conformal universe, up to fourth order i...

Show 4 more citing papers

Defrosting in an Emergent Galileon Cosmology
astro-ph.CO 2011-05 conditional novelty 6.0 of 10

Including the universe's expansion makes the minimal Galileon-matter coupling sufficient to end the Galileon Genesis phase and start a radiation-dominated epoch.
Supersymmetric P(X,phi) and the Ghost Condensate
hep-th 2010-12 accept novelty 6.0 of 10

A superfield recipe builds N=1 supersymmetric extensions of P(X,phi) scalar theories, and its ghost-condensate application shows the extra supersymmetric fields pick up wrong-sign gradient terms.
Galileon Cosmology
hep-th 2009-05 conditional novelty 6.0 of 10

Covariantizing the DGP decoupling lagrangian yields a 4D galileon cosmology whose self-interactions screen the scalar at early times, whose expansion history tracks DGP, and which requires a crossover scale above abou...
Single field consistency relation for the 3-point function
astro-ph 2004-07 accept novelty 6.0 of 10

In single-field inflation, the squeezed-limit three-point function of scalar perturbations equals minus the spectral tilt times the product of two power spectra, independent of the inflaton Lagrangian.

How the literature uses it

11 arXiv papers cite this in 11 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 5 sentences without a confident label

Cites it as background 6 papers

An illustrative example of such mechanisms is the cyclic Universe [ref] that, in contrast to the conventional cosmological framework, suggests a periodic history for the Cosmos.

Gravitational waves in a cyclic Universe: resilience through cycles and vacuum state · Introduction · 0.90
The related Ekpyrotic and Cyclic scenarios [ref] are two of the most widely discussed candidates for alternatives to inflation.

Flow in Cyclic Cosmology · Introduction · 0.95
On this basis many alternative cosmological scenarios have been proposed, such as string gas cosmology [ref] , the pre-Big-Bang scenario [ref] , models of Ekpyrotic, cyclic [ref] and bouncing cosmology (see [ref] for a review of older work on bouncing cosmology and [ref] for a review of more recent approaches), and even higher dimensional inflation [ref] .

Defrosting in an Emergent Galileon Cosmology · Introduction · 0.91

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