# Inflationary paradigm in trouble after Planck2013

@article{Ijjas2013InflationaryPI, title={Inflationary paradigm in trouble after Planck2013}, author={Anna Ijjas and Paul J. Steinhardt and Abraham Loeb}, journal={Physics Letters B}, year={2013}, volume={723}, pages={261-266} }

Recent results from the Planck satellite combined with earlier observations from WMAP, ACT, SPT and other experiments eliminate a wide spectrum of more complex inflationary models and favor models with a single scalar field, as reported by the Planck Collaboration. More important, though, is that all the simplest inflaton models are disfavored statistically relative to those with plateau-like potentials. We discuss how a restriction to pl ateau-like models has three independent serious… Expand

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#### References

SHOWING 1-10 OF 157 REFERENCES

Power-law inflation.

- Physics, Medicine
- Physical review. D, Particles and fields
- 1985

A simple inflationary model characterized by a scale factor which grows like Sapprox.t/sup p/, with p a constant greater than one, which is called power-law inflation (PLI), and considers the constraints on this model coming from the requirement of solving the horizon, flatness, ''good'' reheating, and ''convenient'' perturbation-spectrum problems. Expand

Predictions in eternal inflation

- Physics
- 2008

In generic models of cosmological inflation, quantum fluctuations strongly influence the spacetime metric and produce infinitely many regions where the end of inflation (reheating) is delayed until… Expand

Inflationary universe: A possible solution to the horizon and flatness problems

- Physics
- 1981

The standard model of hot big-bang cosmology requires initial conditions which are problematic in two ways: (1) The early universe is assumed to be highly homogeneous, in spite of the fact that… Expand

Inflationary Theory and Alternative Cosmology

- Physics
- 2002

Recently Hollands and Wald argued that inflation does not solve any of the major cosmological problems. We explain why we disagree with their arguments. They also proposed a new speculative mechanism… Expand

Cosmological implications of the Higgs mass measurement

- Physics
- 2007

We assume the validity of the Standard Model up to an arbitrary high-energy scale and discuss what information on the early stages of the Universe can be extracted from a measurement of the Higgs… Expand

Eternal inflation and its implications

- Physics, Economics
- 2007

I summarize the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the… Expand

Inflation and eternal inflation

- Physics
- 2000

Abstract The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal… Expand

On the Degree of Generality of Inflation in Friedmann Cosmological Models with a Massive Scalar Field

- Physics
- 1988

Friedmann cosmological models with a massive minimally coupled scalar field are investigated by numerical methods. It is indicated that the majority of the solutions undergo the inflationary stage in… Expand

Improvement on cosmological chaotic inflation through nonminimal coupling.

- Physics, Medicine
- Physical review. D, Particles and fields
- 1990

Non-minimal coupling may provide a relatively simple solution to the long-standing problem of excessive density perturbations in inflationary models. Expand

Can the universe afford inflation

- Physics
- 2004

Cosmic inflation is envisioned as the 'most likely' start for the observed universe. To give substance to this claim, a framework is needed in which inflation can compete with other scenarios and the… Expand