The Milne cosmological model follows from negative gravity charge particles

There is negligible extra inertia in a linear movement of a point test mass, compared to the inertia when a small shell of mass expands and contracts.

In our previous blog post we claimed that having negative gravity charge particles in dark matter and demanding that the total gravity charge of the universe is zero is the most beautiful way to explain the lack of extra inertia.

https://arxiv.org/abs/1110.3054

Aurelien Benoit-Levy and Gabriel Chardin (2012) have studied just this type of a cosmology.

Since gravity charges cancel each other at a large scale in the universe, the expansion has a constant velocity for a typical baryon. Gravity does not slow down the expansion. Neither is there a cosmological constant to speed up the expansion.

https://en.wikipedia.org/wiki/Milne_model

Edward Arthur Milne introduced the constant expansion velocity model in 1935.

Benoit-Levy and Chardin write that the uniformity of the universe can be explained without inflation in the Milne model.

Let us list advantages of the Milne model:

1. The Milne model explains why a point test mass in a linear movement has no extra inertia compared to an expanding and contracting small spherical shell of masses.

2. There is no ad hoc cosmological constant Λ.

3. No need for ad hoc inflation.

4. Gravity charges are like electric charges: charges cancel each other out at the large scale.

5. The Milne model is consistent with the ages of the oldest stars ~ 14 billion years.

6. The Milne model is simple. The metric for static observers is the Minkowski metric.

Disadvantages:

1. We have to assume ad hoc dark matter which has negative gravity charges.

2. The Milne model says that, in comoving coordinates with matter, the spatial metric has negative curvature. This may contradict some CMB data.

We need to check if there are any observations which might refute the Milne model.