# Thermal Tachyacoustic Cosmology

@article{Agarwal2014ThermalTC, title={Thermal Tachyacoustic Cosmology}, author={Abhineet Agarwal and Niayesh Afshordi}, journal={Physical Review D}, year={2014}, volume={90}, pages={043528} }

Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5, Canada(Dated: June 5, 2014)An intriguing possibility that can address pathologies in both early universe cosmology (i.e. thehorizon problem) and quantum gravity (i.e. non-renormalizability), is that particles at very highenergies and/or temperatures could propagate arbitrarily fast. A concrete realization of this pos-sibility for the early universe is the Tachyacoustic (or Speedy Sound) cosmology, which…

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## References

SHOWING 1-10 OF 13 REFERENCES

and M

- Sasaki,
- 2014

and C

- Vafa, Phys.Rev.Lett. 97, 021302
- 2006

JCAP 1111

- 049
- 2011

JCAP 0312

- 002
- 2003

arXiv:1403.3985 [astro-ph.CO

- (BICEP2 Collaboration),
- 2014

and C

- R. Contaldi, Class.Quant.Grav. 24, 3691
- 2007

arXiv:1303.5076 [astro-ph.CO

- (Planck Collaboration),
- 2013

and R

- H. Brandenberger, Phys.Rept. 215, 203
- 1992