Short-range interactions are irrelevant at the quasiperiodicity-driven Luttinger liquid to Anderson glass transition

We show that short-range interactions are irrelevant around gapless ground-state delocalization-localization transitions driven by quasiperiodicity in interacting fermionic chains. In the presence of interactions, these transitions separate Luttinger liquid and Anderson glass phases. Remarkably, close to criticality, we find that excitations become effectively noninteracting. By formulating a many-body generalization of a recently developed method to obtain single-particle localization phase diagrams, we carry out precise calculations of critical points between Luttinger liquid and Anderson glass phases and find that the correlation length critical exponent takes the value ν=1.001±0.007, compatible with ν=1 known exactly at the noninteracting critical point. We also show that other critical exponents, such as the dynamical exponent z and a many-body analog of the fractal dimension are compatible with the exponents obtained at the noninteracting critical point. Noteworthy, we find that the transitions are accompanied by the emergence of a many-body generalization of previously found single-particle hidden dualities. Finally, we show that in the limit of vanishing interaction strength, all finite-range interactions are irrelevant at the noninteracting critical point.