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We reconsider the hypothesis of a vast cometary reservoir surrounding theSolar System - the Oort cloud of comets - within the framework of MilgromianDynamics (MD or MOND). For this purpose we built a numerical model of the cloudassuming QUMOND, a modified gravity theory of MD. In the modified gravityversions of MD, the internal dynamics of a system is influenced by the externalgravitational field in which the system is embedded, even when this externalfield is constant and uniform, a phenomenon dubbed the external field effect(EFE). Adopting the popular pair $\nu(x)=[1-\exp(-x^{1/2})]^{-1}$ for the MDinterpolating function and $a_{0}=1.2\times10^{-10}$ m s$^{-2}$ for the MDacceleration scale, we found that the observationally inferred Milgromian cloudof comets is much more radially compact than its Newtonian counterpart. Thecomets of the Milgromian cloud stay away from the zone where the Galactic tidecan torque their orbits significantly. However, this does not need to be anobstacle for the injection of the comets into the inner solar system as the EFEcan induce significant change in perihelion distance during one revolution of acomet around the Sun. Adopting constraints on different interpolating functionfamilies and a revised value of $a_{0}$ (provided recently by the Cassinispacecraft), the aforementioned qualitative results no longer hold, and, inconclusion, the Milgromian cloud is very similar to the Newtonian in itsoverall size, binding energies of comets and hence the operation of theJupiter-Saturn barrier. However, EFE torquing of perihelia still play asignificant role in the inner parts of the cloud. Consequently Sedna-likeorbits and orbits of large semi-major axis Centaurs are easily comprehensiblein MD. In MD, they both belong to the same population, just in different modesof their evolution.

Sedna and the cloud of comets surrounding the Solar System in Milgromian dynamics