Is it possible that dark matter and dark energy come from the same dark particle?

Question

I've skimmed articles/blogs and watched videos around this issue, and the universal consensus is that dark matter and dark energy are two different things >> DM is attractive while DE is repulsive.

LOGIC 1: Dark matter is attractive because it resides/surrounds within an individual galaxy's volume space. On the other hand, dark energy is "repulsive" (it pulls galaxies away from each other) because it is outside the volume space of the observable Universe.

Following this logic, as the universe expands, the dark energy that falls into the space volume of individual galaxies will form part of its dark matter and becomes "attractive".

LOGIC 2: If dark energy is really purely repulsive, then it must have started tearing apart visible matter on the outer edges of the Universe.

Logic 1 looks more plausible to me. Following Logic 1, is it possible that a common yet unknown particle is the source of both DM and DE?

Answer 1

Not in the sense that you ask. In cosmology, matter is anything whose energy density scales with $a^{-3}$, where $a$ is the scale factor. Dark matter is called dark matter because it is an unknown component of the universe that nonetheless obeys this scaling relation. On the other hand, dark energy does not scale - it is proportional to $a^0$. See the technical definition section of the Wikipedia articles on dark matter and dark energy. Any particle would necessarily be dark matter but not dark energy, because the density of any particle in a box decreases as you increase the size of the box.

However, there are theories that attempt to explain dark matter & dark energy with a single framework. Again, see Wikipedia on dark fluid.

Answer 2

No. Dark matter is mass that can move through spacetime. It scales with the expansion of the universe $a$ as $a^{-3}$. In contrast, dark energy is a property of spacetime itself and scales not at all with the expansion of the universe (which is why it's also called a cosmological constant)

Answer 3

It's possible that dark matter can be converted into dark energy and vice versa, just like baryonic matter can change to energy and energy into matter. I don't see dark matter and dark energy being much different in this regard. But on the other hand, dark energy and dark matter may actually interchangeable in the way standard energy and matter are, the "dark" in the terms 'dark matter' and 'dark energy' does mean unknown, after all.