Higgs inflation and teleparallel gravity

摘要: Teleparallel gravity is a formulation of general relativity that physically equivalent to metric if the gravitational action has Einstein-Hilbert form and matter minimally coupled. However, scalar fields generally couple directly connection, breaking equivalence. In particular, this happens for Standard Model Higgs. We show teleparallel theory with non-minimally coupled field no linear perturbations, therefore cannot give successful inflation, unless non-minimal coupling functions satisfy particular relation. If relation satisfied, Higgs inflation can an arbitrarily large tensor-to-scalar ratio $r$. Our results also apply $f(T)$ theories, as they are scalar-tensor theories written in different coordinates. discuss generalisation more complicated actions.