prompter: What are dark matter and dark energy and how do they affect the structure and evolution of the cosmos?

assistant: Dark matter is a form of matter that does not emit, absorb, or reflect light, which makes it invisible to telescopes.  Despite this, its existence is inferred from its gravitational effects matter that is visible.

Dark energy is an enigmatic form of energy that permeates all of space and is responsible for the observed acceleration of the expansion of the universe.

Together, dark matter and dark energy profoundly impact the structure and evolution of the universe.  Dark matter provides the gravitational force needed for galaxy formation and helps maintain their structure.  Dark energy counteracts the attractive force of gravity, causing the universe to expand at an accelerating rate. 

The interplay between dark matter and dark energy determines the fate of the universe.  If dark energy continues to dominate, the universe will keep expanding faster and faster, eventually leading to a scenario known as the "Big Rip."

prompter: so are Dark energy and dark matter two completely different things?

assistant: Dark energy and dark matter are separate things that arise to solve different problems.

Dark energy is the rational for tuning the cosmological constant term in Einstein's field equations to explain the observed expansion of the universe.  (Antidotally, the cosmological constant is a term Einstein added to make the universe not expand or contact in his model.  He later regretted the addition, terming it "his greatest blunder", but it later became a tool to address this issue.)

Dark matter is the rational to explain a wide array of observations where gravitational calculations suggest there is much more mass than we currently estimate from visual observations.  This manifests as a line in the balance sheet for the mass in the universe as cosmologist's make an accounting of it.

As the names suggest, we don't know much about dark energy or dark matter, and many theories abound to try to explain these discrepancies.  There may be a relationship between the two, but such a link is not implied a priori.

prompter: Are there some attempts at theory for dark matter?
And if so what were the problem with those theories?

assistant: Whilst we can't say for certain, we generally don’t integrate them together.

You can always make a “unified model” of dark matter and dark energy, and many physicists have done so, but there’s no compelling motivation to do so. If you think there is, you’ll have to provide a compelling answer to the following question:

“why is it more compelling to introduce one new, unified component that has two free parameters to it — one to explain the “dark matter” effects and another one to explain the “dark energy” effects — than it is to introduce two independent components that evolve independently of one another?”

If dark matter and dark energy are somehow related to one another, that relationship is subtle and not obvious to physicists given our current understanding of nature. Until we have some evidence that these two things actually are related somehow, we have to take the conservative approach.

prompter: Is there a known connection between dark matter and black holes?

assistant: Dark matter and dark energy are two mysterious substances that make up most of the universe. Dark matter is invisible but has mass and gravity, and it affects the structure and evolution of galaxies and galaxy clusters. Dark energy is a force that opposes gravity and causes the universe to expand faster over time. Scientists do not know what dark matter and dark energy are made of, but they are trying to find out by observing their effects on the cosmos.

prompter: hlo