# Difference between single mixture gaussian and regular gaussian distribution

I am reading a paper, and it is said "state observationprobability densities were single mixture Gaussian observation densities". My question is: Isn't a single mixture gaussian the same that a regular 1-D gaussian?

• I single mixture sounds to me like a mixture of two different Gaussian distributions which may not look like a single Gaussian distribution at all. It is likely to be bimodal. The existence of a mean and covariance matrix can happen with a mixture distribution without it being a single Gaussian distribution. – Michael R. Chernick Aug 14 '17 at 16:47

Without knowing which paper you are talking about, I would guess that the authors modeled state observation distribution as a single gaussian, but wanted to hint that the model could be generalized to a gaussian mixture with $n > 1$ components, even though they did not do so.