Abstract:
Let $\xi_1,\xi_2,\dots$ be a sequence of independent copies of a random
variable (r.v.) $\xi$, ${S_n=\sum_{j=1}^n\xi_j}$,
$A(\lambda)=\ln\mathbf{E}e^{\lambda\xi}$,
$\Lambda(\alpha)=\sup_\lambda(\alpha\lambda-A(\lambda))$ is the
Legendre transform of $A(\lambda)$. In this paper, which is partially a review to some extent, we consider generalization of the exponential
Chebyshev-type inequalities $\mathbf{P}(S_n\geq\alpha n)\leq\exp\{-n\Lambda(\alpha)\}$, $\alpha\geq\mathbf{E}\xi$, for
the following three cases: I. Sums of random vectors, II. stochastic
processes (the trajectories of random walks), and III. random fields associated with
Erdős–Rényi graphs with weights. It is shown that these
generalized Chebyshev-type inequalities enable one to get exponentially
unimprovable upper bounds for the probabilities to hit convex sets and also
to prove the large deviation principles for objects mentioned in I–III.
Keywords:exponential Chebyshev-type inequality, large deviation principle, local large
deviation principle, random walk, random field, Erdős–Rényi graphs.