DSR as an explanation of cosmological structure

Understand

Deformed special relativity (DSR) is one of the possible realizations of a varying speed of light (VSL).

• It deforms the usual quadratic dispersion relations so that the speed of light becomes energy dependent, with preferred frames avoided by postulating a non-linear representation of the Lorentz group.
• The theory may be used to induce a varying speed of sound capable of generating (near) scale-invariant density fluctuations, as discussed in a recent Letter.
• We identify the non-linear representation of the Lorentz group that leads to scale-invariance, finding a universal result.