Lecture Notes on Non-Gaussianity

@inproceedings{Byrnes2014LectureNO,
  title={Lecture Notes on Non-Gaussianity},
  author={Christian T. Byrnes},
  year={2014}
}
We discuss how primordial non-Gaussianity of the curvature perturbation helps to constrain models of the early universe. Observations are consistent with Gaussian initial conditions, compatible with the predictions of the simplest models of inflation. Deviations are constrained to be at the sub percent level, constraining alternative models such as those with multiple fields, non-canonical kinetic terms or breaking the slow-roll conditions. We introduce some of the most important models of… 

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References

SHOWING 1-10 OF 91 REFERENCES

Local non-Gaussianity from inflation

The non-Gaussian distribution of primordial perturbations has the potential to reveal the physical processes at work in the very early universe. Local models provide a well-defined class of

Conditions for large non-Gaussianity in two-field slow-roll inflation

We study the level of primordial non-Gaussianity in slow-roll two-field inflation. Using an analytic formula for the non-linear parameter fNL in the case of a sum or product separable potential, we

Observational signatures and non-Gaussianities of general single-field inflation

We perform a general study of primordial scalar non-Gaussianities in single-field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of

Inflationary prediction for primordial non-gaussianity.

We extend the deltaN formalism so that it gives all of the stochastic properties of the primordial curvature perturbation zeta if the initial field perturbations are Gaussian. The calculation

Primordial Non-Gaussianities from Inflation Models

This is a pedagogical review on primordial non-Gaussianities from inflation models. We introduce formalisms and techniques that are used to compute such quantities. We review different mechanisms

Primordial non-Gaussianity in the Large Scale Structure of the Universe

Primordial non-Gaussianity is a potentially powerful discriminant of the physical mechanisms that generated the cosmological fluctuations observed today. Any detection of significant non-Gaussianity

Non-Gaussianity from the inflationary trispectrum

We present an estimate for the non-linear parameter τNL, which measures the non-Gaussianity imprinted in the trispectrum of the comoving curvature perturbation, ζ. Our estimate is valid throughout

Non-Gaussianities in models with a varying inflaton decay rate

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider both the

Inflationary models inducing non-Gaussian metric fluctuations

These models are realizations of mechanisms in which non-Gaussianity is first generated by a light scalar field and then transferred into curvature fluctuations to construct explicit models of multi-field inflation in which the primordial metric fluctuations do not necessarily obey Gaussian statistics.

Scale-dependent non-Gaussianity probes inflationary physics

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new
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