  This note presents sharp inequalities for deviation probability of a general
quadratic form of a random vector \(\xiv\) with finite exponential moments. The
obtained deviation bounds are similar to the case of a Gaussian random vector.
The results are stated under general conditions and do not suppose any special
structure of the vector \(\xiv\). The obtained bounds are exact
(non-asymptotic), all constants are explicit and the leading terms in the
bounds are sharp.
