Chaotic inflation with four-form couplings

We consider chaotic inflation models with a pseudoscalar field containing the general couplings to the four-form flux. The four-form mixing with the pseudoscalar field induces a quadratic potential for inflaton while the coexisting four-form mixing with graviton generates a nonminimal gravity coupling for inflaton. The shift symmetry is respected by the derived inflaton couplings, and it is broken spontaneously only by the fixed four-form flux. We discuss the success of inflationary predictions and robustness against higher order terms. Finally, the built-in reheating mechanism is also addressed.