Anisotropy in solid inflation

Understand

In the model of solid / elastic inflation, inflation is driven by a source that has the field theoretical description of a solid.

• To allow for prolonged slow roll inflation, the solid needs to be extremely insensitive to the spatial expansion.
• We point out that, because of this property, the solid is also rather inefficient in erasing anisotropic deformations of the geometry.
• This allows for a prolonged inflationary anisotropic solution, providing the first example with standard gravity and scalar fields only which evades the conditions of the so called cosmic no-hair conjecture.