View source for Linear independence, measure of

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''of numbers $\alpha_1,\ldots,\alpha_n$''

{{MSC|11J}}

The function
$$
L(\alpha_1,\ldots,\alpha_n|H) = L(H) = \min |a_1 \alpha_1 + \cdots + a_n \alpha_n|
$$
where the minimum is taken over all possible sets of integers $a_1,\ldots,a_n$, not all zero, satisfying the conditions
$$
|a_i| \le H
$$
It is known that
$$
L(\alpha_1,\ldots,\alpha_n|H) < (|a_1| + \cdots + |a_n|) H^{\tau(n-1)}
$$
where $\tau=1$ if all the numbers $\alpha_1,\ldots,\alpha_n$ are real, and $\tau=\frac12$ otherwise. To obtain lower bounds on $L(\alpha_1,\ldots,\alpha_n|H)$ with respect to the parameter $H$ for specific sets of numbers $\alpha_1,\ldots,\alpha_n$ is one of the problems of the theory of [[Diophantine approximations]].