Kinetically modified Palatini inflation meets ACT data

We show that the coexistence of a non-minimal coupling to gravity $f_R=1+c_R{\varphi }^{n/2}$ with a kinetic mixing of the form $f_K=f_R^m$ – where $n=2$ and 4 and $0.5\le m\le 10$ – reconciles chaotic inflation based on the ${\varphi }^n$ potential with the recent ACT results, if we adopt the Palatini formulation of gravity. The attainment of inflation allows for subplanckian inflaton values and energy scales below the cut-off scale of the corresponding effective theory. The model can be also embedded in supergravity by introducing two chiral superfields and a monomial superpotential, linear with respect to the inflaton-accompanying field. Its stabilization is achieved thanks to a compact contribution to the Kähler potential, whose the inflationary part includes an holomorphic logarithmic term and a real one multiplying a shift-symmetric quadratic polynomial term.