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Related Experiment Video

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Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

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Published on: July 2, 2012

Local observation in eternal inflation.

James Hartle¹, S W Hawking, Thomas Hertog

¹Department of Physics, University of California, Santa Barbara, California 93106, USA.

Physical Review Letters

|May 13, 2011

Summary

The no-boundary wave function aids in predicting cosmological observations within eternal inflation models. It suggests a tensor-to-scalar ratio of approximately 10% for local universe predictions.

Area of Science:

Cosmology
Theoretical Physics
Quantum Gravity

Background:

Eternal inflation models propose vast multiverses with varying physical laws.
The landscape of string theory suggests numerous possible vacuum states.
Predicting observable quantities in such models remains a significant challenge.

Purpose of the Study:

To utilize the no-boundary wave function to calculate cosmological predictions within landscape models.
To investigate the impact of eternal inflation on observable homogeneity.
To establish a measure for local cosmological observations.

Main Methods:

Employing the no-boundary wave function formalism.
Analyzing landscape models with multiple eternal inflation regions.

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Calculating fluctuations within the past light cone.

Main Results:

Small departures from homogeneity can be calculated despite large super-horizon fluctuations.
The dominant contribution arises from histories exiting inflation at the lowest potential value.
A tensor-to-scalar ratio of approximately 10% is predicted for a class of models.

Conclusions:

The no-boundary wave function provides a method for predicting local cosmological observations.
This approach offers a way to constrain landscape models through observational data.
The predicted tensor-to-scalar ratio offers a testable prediction for future observations.