Is flat rotation curve a sign of cosmic expansion?

TL;DR

This paper explores four alternative theories linking cosmic expansion to galactic rotation curves, challenging the conventional dark matter explanation and proposing modifications to fundamental principles and models.

Contribution

It introduces four novel hypotheses connecting cosmic expansion with galactic dynamics, offering new perspectives on the rotation curve problem.

Findings

Proposes a modified equivalence principle in an accelerating universe.

Suggests a variable mass system dynamics for galactic halos.

Recommends replacing physical radius with comoving radius in models.

Abstract

Four alternative proposals as the possible solutions for the rotation curve problem are introduced on the basis of assumption that the cosmic expansion is engaged with the galactic dynamics over the halo. The first one proposes a modification of equivalence principle in an accelerating universe. The second one proposes a modification of Mach principle in an expanding universe. The third one proposes a dynamics of variable mass system for the halo in an expanding universe, and the fourth one proposes the replacement of physical radius with comoving one over the halo, in an expanding universe.