Does $\Lambda$CDM include inflation? $\Lambda$CDM obviously includes dark energy (the $\Lambda$) as well as cold dark matter (CDM). Does it also include cosmic inflation?
I've not seen a clear answer to this. Wikipedia's article on Lambda-CDM says in the lede that Lambda-CDM can be extended to include inflation (i.e. it doesn't per se include cosmic inflation). But then in the next section it contradicts itself by saying "The model includes ... an exponential expansion of space [shortly after the big bang] by a scale multiplier of $10^{27}$ or more, known as cosmic inflation." I also suspect most cosmologists will agree that the observational evidence behind inflation is less established than that behind dark matter and dark energy.
Does $\Lambda$CDM include cosmic inflation? If so, why isn't it referred to as $\Lambda$CDMI?
 A: The $\Lambda CDM$ cosmological model is a pattern of the evolution of the cosmos parameterized by a cosmological constant $\Lambda$ describing the vacuum energy (dark energy), ordinary matter (baryonic) and cold nonbaryonic dark matter (CDM) inferred to match the observed matter density. The picture in which, as per current cosmological epoch, roughly matter density $\Omega_M = 0.3$, vacuum energy density $\Omega_\Lambda = 0.7$, radiation density $\Omega_R = 0.0001$ (negligible), fits an impressive variety of observational data and implies a flat universe as well.  
In itself the model is not asking for cosmic inflation, however the flatness of the universe, its homogeneity and isotropy on a large scale raised the two problems of unnaturalness: the so called "flatness problem" and "horizon problem" (The CMB, cosmic microwave background, is isotropic to a high degree). Why the initial conditions of the universe were so finely tuned? As this seems unlikely, a more likely scenario is a dynamical mechanism that can take a wide spectrum of initial conditions and evolve them toward flatness and homogeneity/isotropy. The inflationary universe provides such mechanism, even if its demonstration is still far to be achieved.
