Dark matter interacts with gravity in a non-local way, shows study

Dwarf galaxy. Credit: NASA's Goddard Space Flight Center/Jenny Hottle.

Ever wondered about the mysteries of the universe and how everything, near or far, is connected?

The answer lies in gravity, a force that pulls everything towards everything else. It’s like the invisible threads that hold the stars, planets, and galaxies in their place.

Sir Isaac Newton, a brilliant scientist from centuries ago, came up with the idea that gravity works instantly over any distance.

But a man named Albert Einstein thought differently.

He believed gravity wasn’t just some magical force acting instantly over great distances, but more like a bending and curving of space and time caused by massive objects like stars and planets.

According to him, things don’t just get affected from afar instantly, it’s the nearby stuff that matters the most. This is known as the principle of locality.

However, in the world of the very small – the quantum world – things are a bit weirder. Here, particles can influence each other instantly, even over large distances.

This strange occurrence is called non-locality, and it’s a key part of quantum physics.

Now, some students and their professor from a place called SISSA—Scuola Internazionale Superiore di Studi Avanzati—have made an exciting discovery.

They think that dark matter, a mysterious substance that makes up about 85% of the universe, also behaves non-locally. In simpler terms, dark matter feels the influence of everything in the universe, near or far.

Their study was published in The Astrophysical Journal.

Even though dark matter is everywhere and helps galaxies form, we still know very little about it. But Francesco Benetti, Giovanni Gandolfi, and their teacher, Andrea Lapi, suggest that looking at dark matter through the lens of non-locality could reveal its secrets.

These researchers propose a new model where dark matter in a galaxy interacts with gravity from all over the universe. It’s like all the matter in the universe is guiding the movement of dark matter in each galaxy.

To explain this idea, the researchers used a type of math called fractional calculus, a tool that hasn’t been used much in astrophysics before.

They found that this new model worked better than our traditional understanding of gravity in predicting the motion of stars in many different galaxies.

They believe that this strange non-local behavior is a result of how dark matter particles work together, especially in small galaxies. This could give us important clues about what dark matter is.

But there are still many questions. For example, how exactly does non-locality happen? How does it affect larger structures, like groups of galaxies, or gravitational lensing, which lets us see very far away objects?

Additionally, this new idea might require us to rethink our basic understanding of the universe, also known as the standard model of cosmology.

The researchers plan to continue their work to answer these questions and more. They believe this idea of non-locality could answer other big questions about the universe.

Every new discovery about the nature of dark matter brings us one step closer to understanding the mysteries of our universe. As research continues, we’re excited to see what new perspectives and insights will be revealed.