An Alternative to Dark Matter and Dark Energy: Scale-Dependent Gravity in Superfluid Vacuum Theory

We derive an effective gravitational potential, induced by the quantum wavefunction of a physical vacuum of a self-gravitating configuration, while the vacuum itself is viewed as the superfluid described by the logarithmic quantum wave equation. We determine that gravity has a multiple-scale pattern, to such an extent that one can distinguish sub-Newtonian, Newtonian, galactic, extragalactic and cosmological terms. The last of these dominates at the largest length scale of the model, where superfluid vacuum induces an asymptotically Friedmann–Lemaître–Robertson–Walker-type spacetime, which provides an explanation for the accelerating expansion of the Universe. The model describes different types of expansion mechanisms, which could explain the discrepancy between measurements of the Hubble constant using different methods. On a galactic scale, our model explains the non-Keplerian behaviour of galactic rotation curves, and also why their profiles can vary depending on the galaxy. It also makes a number of predictions about the behaviour of gravity at larger galactic and extragalactic scales. We demonstrate how the behaviour of rotation curves varies with distance from a gravitating center, growing from an inner galactic scale towards a metagalactic scale: A squared orbital velocity’s profile crosses over from Keplerian to flat, and then to non-flat. The asymptotic non-flat regime is thus expected to be seen in the outer regions of large spiral galaxies.

Superfluid vacuum theory and deformed dispersion relations

Using the logarithmic superfluid model of physical vacuum, one can formulate an essentially quantum post-relativistic theory, which successfully recovers Einstein’s theory of relativity in low-momenta limit, but otherwise has different foundations and predictions. We present an analytical example of the dispersion relation and show that it should have a Landau form which ensures the suppression of dissipative fluctuations. We show that in the low-momentum sector of the theory, a dispersion relation becomes relativistic with small deformations, such that a photon acquires effective mass, but a much more complex picture arises at large momenta.

Superfluid Quantum Vacuum Model,Mass-Energy Equivalence, Inertia, and Gravity

In this paper, we present the Superfluid Vacuum model in order to explain mass-energy equivalence, inertia and gravity. We found that this model confirms that inertial mass and gravitational mass are equal and have this origin in the vacuum fluctuations caused by the variable density of vacuum.

Hydrodynamics of the physical vacuum: Dark matter is an illusion

The relativistic hydrodynamical equations are being examined with the aim of extracting the quantum-mechanical equations (the relativistic Klein–Gordon equation and the Schrödinger equation in the non-relativistic limit). In both cases we find the quantum potential, which follows from pressure gradients within a superfluid vacuum medium. This special fluid, endowed with viscosity allows to describe emergence of the flat orbital speeds of spiral galaxies. The viscosity averaged on time vanishes, but its variance is different from zero. It is a function fluctuating about zero. Therefore, the flattening is the result of the energy exchange of the torque with zero-point fluctuations of the physical vacuum on the ultra-low frequencies.