The Swampland Distance Conjecture and Towers of Tensionless Branes

<!--HTML-->The Swampland Distance Conjecture states that at infinite distance in the scalar moduli space an infinite tower of particles becomes exponentially massless. In the context of 4d Calabi-Yau compactifications we find that not only towers of particles, but also towers of strings and domain walls generally become tensionless at different infinite distance points. For $\mathcal{N}=1$ Calabi-Yau orientifolds in type IIA we present the monodromy orbits of domain walls. Finally, we show the structure of energy scales of these towers at different infinite distance points in simple toroidal compactifications, finding that they may occur at the KK or the fundamental string scales. We end with some comments on possible implications of the presence of these towers of extended objects (emergence, non-geometric fluxes, 4d vacua…).