Constructs a time_series_model for white noise with variance sigma2.
The process is defined as
\(X_t \stackrel{\text{i.i.d.}}{\sim} N(0, \sigma^2)\)
with autocovariance
\(\gamma(h) = \mathrm{cov}(X_t, X_{t+h}) = \sigma^2 \mathbf{1}\{h=0\}\)
Constructs a time_series_model for white noise with variance sigma2.
The process is defined as
\(X_t \stackrel{\text{i.i.d.}}{\sim} N(0, \sigma^2)\)
with autocovariance
\(\gamma(h) = \mathrm{cov}(X_t, X_{t+h}) = \sigma^2 \mathbf{1}\{h=0\}\)