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Seminar on Probability Theory and Mathematical Statistics
November 21, 2011 11:00, St. Petersburg, PDMI, room 311 (nab. r. Fontanki, 27)
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Об оценке преобразования Стилтьеса спектральной меры вблизи вещественной оси и оценки скорости сходимости в полукруговом законе и законе Марченко–Пастура
A. N. Tikhomirov |
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Abstract:
Let $\mathbf X=(X_{jk})$ denote a Hermitian random matrix with entries $X_{jk}$, which are independent for $1\le j\le k$. We consider
the rate of convergence of the empirical spectral distribution function of
the matrix $\mathbf X$ to the semi-circular law assuming that $\mathbb E X_{jk}=0$,
$\mathbb E X_{jk}^2=1$ and that the distributions of the matrix elements $X_{jk}$ have a uniform
sub exponential decay in the sense that there exists a constant $\varkappa>0$ such that for any $1\le j\le k\le n$ and any $t\ge 1$ we have
$$
\Pr\{|X_{jk}|>t\}\le \varkappa^{-1}\exp\{-t^{\varkappa}\}.
$$
By means of a short recursion argument it is shown that the
Kolmogorov distance between the empirical spectral
distribution of the Wigner matrix $\mathbf W=\frac1{\sqrt n}\mathbf X$
and the semicircular law is of order $O(n^{-1}\log^b n)$ with some
positive constant $b>0$.
Similar result is obtaned for sample covariance matrices.
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