Speaker
Description
We study limits of vanishing Yukawa couplings in Quantum Gravity, using as a laboratory type IIA orientifolds. We show that in the limit Y → 0 there are some towers (dubbed gonions) that become asymptotically massless, while at the same time, the kinetic term of some chiral fields becomes singular. For limits parametrised by a large complex structure saxion u, Yukawa couplings have a behavior of the form Y ∼ 1/u^r. Moreover, some of the gauge couplings associated with the Yukawa vanish in this limit. The lightest gonion scales are of order mgon ∼ g^s with s > 1, verifying the magnetic WGC with room to spare and with no need of its tower/sublattice versions. All these results may be very relevant for phenomenology, given that some of the Yukawa couplings in the Standard Model are very small.
