Are there any theories as to what dark matter and dark energy are?

With regard to dark matter, I answer your question here: Also included in that answer is a description of the leading experiments aiming to detect dark matter.

Dark energy and dark matter are terms given in order to account for the mass discrepancy and accelerated expansion of known universe. Dark matter forms nearly 27% and dark energy around 68% is dark energy. Together they form 95% of the known universe. Pretty amazing huh. It just goes to show that all that we can see and measure is just 5% of the universe. When astronomers were looking through the space and stuff they found a lot of matter missing. They could see it's effect but were not able to pinpoint to as from where they are originating. Like when they measured mass of a galaxy by its effect on microwave background radiation ( gravitational lensing and stuff) they found that lot of matter is unaccounted for. And since they had no clue to what it is other than its not visible and so they aptly named it dark matter. Coming to dark energy, the universe is expanding. That everyone knows nowadays. Except maybe few ( supporter of steady states and ummm hardcore religious people). But the problem arose on the point that the expansion is accelerating. And the visible energy couldn't explain from where the hell is the energy coming for this acceleration. Visible energy couldn't sustain such high level of expansion. And again this invisible energy couldn't be observed. So they hypothesized that it's very kinda very rarified. Like so rarified that you might find handful of this energy particle per metre cube. And they don't interact with matter. All in all no way to see them. And hence this aptly has named dark energy. Duh!

There is a reason why we call them Dark Energy and Dark Matter, It is because we are not entirely sure of what they are and their characteristics. Said that  its existence and properties are inferred from its gravitational  effects on visible matter, radiation, and the large-scale structure of  the universe and dark matter is estimated to constitute 84.5% of the total matter in the universe. Made of : According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particles. The search for this particle, by a variety of means, is one of the major efforts in Particle Physics today.

Too many theories Here are two review papers on dark matter http://arxiv.org/pdf/hep-ph/0404175v2.pdf http://arxiv.org/pdf/1201.3942v1.pdf Here is a review paper on dark energy http://arxiv.org/pdf/1209.0922v1.pdf There are probably several dozen different ideas that are currently viable, and probably hundreds of different ideas that have been rejected.  It's not coming up with ideas as to what they might be that's a problem.  Theorists are a pretty creative bunch.  The hard part is getting the data so that you can cross out explanations. The situation is constantly changing and all of the papers I mentioned will get stale and out of date, but the magic google terms are "dark matter review paper" and "dark energy review paper".

Our Universe is constantly accelerating that is,the Universe is expanding with time.The distance between two distant parts of our universe is going through expansion over a period of time.This is the basis of the famous Big Bang model and various components of this process our explained by the Hubble Law. This model is still prevalent and applicable in the modern world.There are basically four forces that are involved in our Universe: Electro Magnetism Gravitational Weak Nuclear Strong Nuclear Gravitational force helps in binding of matter.Therefor,the gravity must prevent the expansion of the Universe and must slowly recede but it turned out it was accelerating.Now,while there are strong gravitational forces between matter,scientists realized there must be a force which is involved in causing the expansion.This force which seems like anti-gravity , is actually what we call dark energy. Our Universe is composed of 68% dark energy and 5% normal matter. The remaining 27% is composed of something which scientists were unaware of.They put forth a hypothesis that our universe has 27% of matter that does not absorb or emit light or other electromagnetic radiations.They are generally large baryon ix clouds which bend light around them.This is what we call dark matter.(Note:It is not antimatter) Dark matter and Dark energy are both hypothesis.We do not know much about and there is a lot of research going on about them and their properties.

Dark matter covers a failing of relativity to explain the motions of galaxies. The GEM theory (eg http://www.mrelativity.net/ ) uses co-gravitation to get a model of galaxies that does not need dark matter to get the galaxies to spin right, and is also consistant with the perihelion anomaly of mercury.

Well, what is dark energy? More is unknown than is known. We know how much dark energy there is because we know how it affects the Universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the Universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the Universe. Come to think of it, maybe it shouldn't be called "normal" matter at all, since it is such a small fraction of the Universe. One explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not nothing. Space has amazing properties, many of which are just beginning to be understood. The first property that Einstein discovered is that it is possible for more space to come into existence. Then one version of Einstein's gravity theory, the version that contains acosmological constant, makes a second prediction: "empty space" can possess its own energy. Because this energy is a property of space itself, it would not be diluted as space expands. As more space comes into existence, more of this energy-of-space would appear. As a result, this form of energy would cause the Universe to expand faster and faster. Unfortunately, no one understands why the cosmological constant should even be there, much less why it would have exactly the right value to cause the observed acceleration of the Universe. Another explanation for dark energy is that it is a new kind of dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the Universe is the opposite of that of matter and normal energy. Some theorists have named this "quintessence," after the fifth element of the Greek philosophers. But, if quintessence is the answer, we still don't know what it is like, what it interacts with, or why it exists. So the mystery continues.Another explanation for how space acquires energy comes from the quantum theory of matter. In this theory, "empty space" is actually full of temporary ("virtual") particles that continually form and then disappear. But when physicists tried to calculate how much energy this would give empty space, the answer came out wrong - wrong by a lot. The number came out 10120 times too big. That's a 1 with 120 zeros after it. It's hard to get an answer that bad. So the mystery continues. A last possibility is that Einstein's theory of gravity is not correct. That would not only affect the expansion of the Universe, but it would also affect the way that normal matter in galaxies and clusters of galaxies behaved. This fact would provide a way to decide if the solution to the dark energy problem is a new gravity theory or not: we could observe how galaxies come together in clusters. But if it does turn out that a new theory of gravity is needed, what kind of theory would it be? How could it correctly describe the motion of the bodies in the Solar System, as Einstein's theory is known to do, and still give us the different prediction for the Universe that we need? There are candidate theories, but none are compelling. So the mystery continues. The thing that is needed to decide between dark energy possibilities - a property of space, a new dynamic fluid, or a new theory of gravity - is more data, better data.

GravityVortex theory, in accordance to the third law of motion, assumes that All forces involve the transfer of energy or motion. Such transfer requires direct physical contact between core matter particles. Unlike the other known forces, in gravity, the kinetic impact of core matter particles happens in a location removed from P1.The encounter then increases P2,3null space pressure on both objects (this is inevitable as they meet each other on an axis where P2,3 null space pressure originates.) The increase in null space pressure results in the transfer of kinetic energy into P1 until equilibrium is reached between both particles and null space pressure. Increasing tangential acceleration along P2,3 vectors results in negative acceleration on P1 travel. This pushes both particles towards each other along P1 . Or more accurately, it pushes them towards their combined center of prime axis acceleration. This is why objects move in ellipses around each other.Shows increase in P2,3 energy. Results in P1 gravitational acceleration The point to which both objects are drawn is not a straight line between the two, but an intersection along their respective vectors of motion. However with massive objects, there is more force being applied by the sun than the earth. This causes a larger net force being applied to the earth than the sun which results in the appearance of the earth revolving around the sun, when in actuality, both objects are being pushed to a separate location. A stable orbit occurs when the increase of null space pressure which imparts null space pressure to an orbiting body reaches equilibrium, yet the velocity and angle of deflection along P1 prevents the object from a more straight line path towards the center of mass of the two objects. As velocity increases along P1 null space pressure decreases along P2,3. There exists a stable equilibrium factor when the angle of incidence and velocity of an object in relation to the second object prevents a straight line descent into each other. For objects in our solar system, as the object gets closer to the sun, the object’s null space pressure decreases while increasing its relative velocity along P1. It then reaches a point where its velocity along P1 in relation to the sun decreases. This is the results of an increase of null pressure to that object in relation to the sun across P2,3. This causes the object to experience acceleration along the prime axis in the opposite direction of its tangential travel along P1. This is what draws an object back towards the sun after it shoots past it. The stable cycle of increasing and decreasing null force pressures depending on relative distance and velocity between two objects is what causes a stable orbit. Gravity is the net effect of two objects encountering each other off of the prime axis. As two objects impact off the prime axis, they impart energy from one to the other forming equilibrium. To equalize null space pressure between the two objects, kinetic energy is transferred along the prime axis in the opposite direction of the object's natural vector of acceleration. This results the rate and direction of motion between the two objects towards their respective center of acceleration/motion to increase or accelerate. This causes null space pressure to equalize between the two objects and those two objects are then pushed tangentially towards each other along the prime axis. This is why two gravitationally linked objects always appear to be drawn to each other’s center of mass. However, the force is in fact generated by two objects physically encountering one another in a non prime axis vector. Maximum gravity, gravity never reaches infinity. The maximum gravity that an object can create is dependent on the matter within it. Gravity can increase only until the null space pressure across all three axes of either P2,3on the trapped space-time within the core is defeated. Once this occurs, then matter then free to escape the prime axis and enter another prime axis. The rate at which a black hole expels space-time into another prime axis is directly related to the input of space-time into the generating black hole. Until Null space pressure is completely defeated across all 3 axes of either P2,3 that region of expanding space-time is deflected partially off of P1 as Dark matter. Once cosmogenic minimum is reached, space-time erupts along P2 or P3 at all linked spatial coordinates nearly simultaneously. Why does gravity extend over such long distances? [11]Due to such a high amount of null space pressure existing along P2,3 relative to our universe the actual linear distances that an object can travel along those axes is much smaller. So even though matter may have expanded 14 plus billion light years along P1, the actual distance traveled along P2,3 is much smaller.So for example we could say that all the space-time in our universe that travels along P2,3 is still clumped together very closely due to the null space pressure being applied across those axes to space-time being extruded into P1. This is also why even at the outer edge of the galaxy, the classic spiral shape is maintained.The angular deflection towards a center of mass along P1 will always force those particles to create a spiraling vortex pattern. From the smallest structures in the universe to the largest, aggregate forces reflect microscopic forces, and microscopic forces can be easily understood by observing macroscopic events.Singularity, does not exist.Logically speaking, if a place in our universe existed into which an infinitely small space into which an infinite amount of matter could fit, then its event horizon would be infinitely small. However it is clear that black holes do not shrink into infinity, but instead grow over time. What happens in a black hole is the secondary vortex force of gravity draws objects together along the prime axis. According to the Schwarzschild radius calculation (which has been observationally confirmed https://en.wikiversity.org/wiki/Nonstandard_physics/Vortex_Science#cite_note-12):where:rs is the Schwarzschild radius;G is the gravitational constant;M is the mass of the object;c is the speed of light in vacuum.The proportionality constant, 2G/c2, is approximately 1.48×10−27  m/kg, or 2.95 km/Solar mass. where: is the volume of the object if singularity occurs; is its density.This calculation leads to a mathematical paradox. As objects reach a concentration where kinetic motion along P1 becomes impossible, the inertia of that object then deflects a small amount off of the prime axis. It does this a number of times until it reaches a vector where it is only weakly gravitationally bound to the black hole's location on P1. This creates a massive dark matter shell that sends gravitational forces over vast distances in relation to the physical size of the black hole along P1. At a certain size one or more supermassive black holes traveling along one or more prime axes reach sufficient gravitational force individually or through intersection, to overcome the null space pressure along a third prime axis. This results in cosmogenesis. All the gravitationally bound space-time is released along that prime axis forming a universe. Dark matter interaction. [6]Dark matter is simply normal core matter deflected off the prime axis. This is why dark matter creates directional movement towards the center of mass of the larger system. If dark matter was indeed a separate object or material, it then would gravitationally accelerate that object towards that unique dark matter object. This does not occur, instead the observed motion of matter affected by dark matter is always towards the center of mass of standard core matter. Particles that were actually native to P2 or P3 would deflect particles along a P1 vector, however, the vector of movement would be in a direction and velocity that would be measurably different than normal gravitational interaction. Since the center of motion between space-time expanding into P1 and an object that has no P1 interaction is not in our universe, directional motion would tend to be random when it came to gravitational interaction. This is not the case however with dark matter gravitation. By looking at the night sky, one can clearly observe matter clearly being drawn in a spiral towards the central black hole of the galaxy. The rules of gravitational energy transfer remain the same. When dark matter encounters other matter both particles are deflected along the prime axis towards their respective center of motion. In reality, all gravity is caused by dark matter interaction. When our matter particles are traveling along P2,3 they encounter particles from the earth traveling also along P2,3. During this portion of their linear travel they are what scientists now refer to as dark matter. Dark EnergyDark energy refers to the force that drives the expansion of space-time Until this paper, scientists naturally assumed that space-time just grows. They have no idea from where or why. Vortex science has a simple and easily calculable method for determining the rate of space-time expansion and the force that generates it. It is generally accepted that the forces that caused the big bang have long since ended and that we exist on the residual energy from that event.[3] However no matter the amount of energy involved, that number doesn’t reach infinity, and after billions of years of travel across an infinitely large spatial zone, those energies would long since have dissipated. The equation for this is ΔS increases/t . The rate of entropy, or diffusion into lower energy states, increases over time. As the size of the system increases, the rate of ΔS increases up to the speed of light. However the universe is not dead or static. It is a dynamic system that is continuously creating and radiating energy. So what is energy? Energy is motion. Motion of what? As all matter and energy are equivalent, and now space-time itself has been explained as a form of matter, energy is simply the difference in rates of motion of expanding space-time between two or more objects. Thus dark energy is a way to give a name to the space-time erupting from the cores of every particle in our bodies.So why do scientists believe the universe is accelerating? This is a complex question. There may in fact be an inherent acceleration, but relative to the observers within the universe, the expansion of space-time is not really detectable in a normal fashion. So what astronomers have done is determine the gravitational range of matter within galactic clusters. They then found galaxies that were too distant to be gravitationally linked to that cluster. Then it turned out that those galaxies were moving away from each other at a steadily increasing velocity. [13]Now that we know that gravity is due to physical interaction between regions of expanding space-time along the P2,P3 axes. Once outside of the range of that interaction the only forces at work would be the repulsive forces of the two aggregate space-time shells being generated by galaxies. As each space-time shell meets the other the additive force of their impact pushes the core matter that generated that space-time tangentially away from the core matter object that produced the second space-time shell. If neither galaxy had expanding space-time, then the net effect would be closer to a standard velocity, motion would be entirely based on gravitation or inherent inertia. With two radiant and repulsive force generators at work, the net effect is additive resulting in acceleration of those objects away from each other. Thus dark energy is not a separate force at all from any of the known forces, but a logical extension of the known physical properties of matter itself.

At this juncture both the concepts are place holders for our ignorance. With so-called Dark Energy we may end up with some kind of mathematical model that describes,  but does not really tell us what it is or what causes it.  Think of the situation with Newton and gravity.  He formulated a law that described it well,  be Newton admitted he could not figure out what causes it.