Relic gravitational wave spectrum, the trans-Planckian physics and Ho\v{r}ava-Lifshitz gravity

Abstract

We calculate the spectrum of the relic gravitational wave due to the trans-Planckian effect in which the standard linear dispersion relations may be modified. Of the modified dispersion relations suggested in literatures which have investigated the trans-Planckian effect, we especially use the Corley-Jacobson dispersion relations. The Corley-Jacobson type modified dispersion relations can be obtained from Ho\v{r}ava-Lifshitz gravity which is non-relativistic and UV complete. Although it is not clear how the transitions from Ho\v{r}ava-Lifshitz gravity in the UV regime to Einstein gravity in the IR limit occur, we assume Ho\v{r}ava-Lifshitz gravity regime is followed by the inflationary phase in Einstein gravity.Comment: 16 pages, 2 figures; added references and comment