Multi-brid DBI Inflation

Abstract

It is shown that it is possible to apply $\delta \cN$ to some special non-canonic cases. We extended the multi-brid idea to the multi-field separable model with a non-canonical kinetic term, mainly the DBI model. Assuming a specific surface for the end of inflation and introducing new fields, enable us to find an explicit expression for the number of e-folds in terms of the new fields. By using $\delta$N formalism, we arrived at the cosmological parameters. We considered the DBI model for two different limits, viz., speed limit and constant sound speed.