String gas cosmology after Planck

作者：Brandenberger Robert H^*

来源：Classical and Quantum Gravity, 2015, 32(23): 234002.

DOI：10.1088/0264-9381/32/23/234002

• string cosmology
• early Universe
• Planck satellite

We review the status of string gas cosmology (SGC) after the 2015 Planck data release. SGC predicts an almost scale-invariant spectrum of cosmological perturbations with a slight red tilt, like the simplest inflationary models. It also predicts a scale-invariant spectrum of gravitational waves with a slight blue tilt, unlike inflationary models which predict a red tilt of the gravitational wave spectrum. SGC yields two consistency relations which determine the tensor to scalar ratio and the slope of the gravitational wave spectrum given the amplitude and tilt of the scalar spectrum. We show that these consistency relations are in good agreement with the Planck data. We discuss future observations which will be able to differentiate between the predictions of inflation and those of SGC.

• 出版日期2015-12-2
• 单位McGill