An Unexpected Source Might Be Helping The Universe Glow More Than It Should - ScienceAlert

This in itself was not unexpected; this light is called the cosmic optical background, a faint luminescence from all the light sources in the Universe outside our galaxy.

Now, in a new paper, scientists lay out a possible explanation for the optical light excess: a by-product of an otherwise undetectable interaction of dark matter.

"The results of this work," write a team of researchers led by astrophysicist José Luis Bernal of Johns Hopkins University, "provide a potential explanation for the cosmic optical background excess that is allowed by independent observational constraints, and that may answer one of the most long-standing unknowns in cosmology: the nature of dark matter.".

We have many questions about the Universe, but dark matter is among the most vexing.

Roughly 80 percent of the matter in the Universe is dark matter.

The difficulty is in separating them from all the other sources of light in the Universe, and this is where the cosmic optical background comes in.

The work of Bernal and his team was to assess whether axion-like dark matter could possibly be responsible for the extra light.