However, I'm a little hesitant to use these terms when we don't know what is 95% of the matter/energy in the universe. Cosmologists use the term "Precision Cosmology" to describe the fact they can use data from a number of data sets to constraint variables, such as the rest mass of neutrinos, the spacetime curvature of the universe, or the number of neutrino species. However, many of these constraints are are only valid when assuming a certain, rather ad hoc model.

In many respects, this Standard Model of Cosmology, i.e. Lambda CDM, is a great starting point, and most people who use it as a starting point are fully aware of its weakness and eagerly await being able to find corrections to the model. The problem is that it's sometimes referred to as if it were one complete consistent model (or referred to as a complete model once there's this small tweak over here or over there.) However, LCDM is not consistent and is rather ad hoc. The goal of this post is to poke holes in the idea that there is a "Standard Model of Cosmology" in the same sense that there's a "Standard Model of Particle Physics." (Note that the SM of particle physics is much closer to being a standard model...with the big exception being the lack of understanding of neutrino physics, i.e. how heavy are neutrinos and is there CP violation in the neutrino sector?)

So, let's begin with the issues with the Standard Model of Cosmology: i.e. Lambda CDM:

(1) There is no mechanism for making more matter than anti-matter in Standard Model of Cosmology. The LCDM model starts off with an initial difference between matter and anti-matter. The physics required to make more matter than anti-matter is not in the model, and this data set (i.e. the value of the baryon and lepton excess fractions) is excluded when doing "Precision Cosmology."

(2) Cold Dark Matter is thrown in ad hoc. The mass of the dark matter particle is not in the model...it's just assumed to be some >GeV rest mass particle made in between the electro-weak transition and neutrino decoupling from the charged particles. The mechanism for making the cold dark matter is not consistent with the Standard Model of Particle Physics. So, it's interesting that the "Standard Model of Cosmology" so easily throws out the much more well known "Standard Model of Particle Physics." This means that there is no "Standard Model of Cosmo-Particle Physics."

There's also the fact that Cold Dark Matter over-predicts the number of satellite galaxies and over predicts the amount of dark matter in the center of galaxies. But once again, this data set is conveniently excluded when doing "Precision Cosmology" and, worse, the mass of the 'cold dark matter particle' is not even a free variable that Planck or other cosmology groups include in the "Standard Model of Cosmology." There are ten's of free variables that Planck uses to fit their data, but unfortunately, the mass of the dark matter particle is not one of the free variables.

It also appears that, if Dark Energy is not just a constant, then it's not thermodynamically stable (for most values of Wo/Wa.) (See the following article

http://arxiv.org/pdf/1501.03491v1.pdf)

So, this element of the "Standard Model of Cosmology" is an ad hoc constant added to GR. And while it's true that dark energy could just be the energy density of the vacuum of space-time, the particular value favored by LambdaCDM is completely ad hoc. The energy density of space-time appears to be on the order of (2 meV)^4. What's so special about 2 meV?