A Nonlocal Realization of MOND that Interpolates from Cosmology to Gravitationally Bound Systems

Nonlocal modifications of gravity derive from corrections to the quantum gravitational stress tensor which grow nonperturbatively strong during primordial inflation and may persist to the current epoch. Phenomenological constructions have been given that realize MOND in gravitationally bound systems and, separately, reproduce all the cosmological phenomena usually ascribed to dark matter, including the cosmic microwave background radiation, baryon acoustic oscillations and linearized structure formation. In this work we exhibit a single model that interpolates between the two regimes.

💡 Research Summary

The paper proposes a single, fully relativistic, non‑local modification of gravity that simultaneously reproduces the phenomenology of cold dark matter on cosmological scales and the Modified Newtonian Dynamics (MOND) behavior observed in gravitationally bound systems such as galaxies. The motivation stems from the observation that quantum‑gravitational corrections to the stress‑energy tensor grow as powers of the scale factor during primordial inflation, producing logarithmic enhancements that persist to late times. These non‑perturbative effects suggest that the “missing mass” phenomena could be a manifestation of non‑local gravity rather than a new particle species.

The authors first construct a cosmological sector. They introduce a timelike 4‑velocity field uμ defined as the gradient of a scalar ϕ