Abstract:
It is proved that the limit
$$
\lim_{\Delta\to\infty}\sup_\gamma\frac 1\Delta
\int_0^\Delta f\bigl(\gamma(t)\bigr)\,dt,
$$
where $f\colon\mathbb R\to\mathbb R$ is a locally integrable (in the sense of Lebesgue) function with zero mean and the supremum is taken over all solutions of the generalized differential equation $\dot\gamma\in[\omega_1,\omega_2]$, coincides with the limit
$$
\lim_{T\to\infty}\sup_{c\ge0}\varphi_f(k,T,c),
$$
where
$$
\varphi_f=\frac{(k-1)\overline I_f(T,c)}
{1+(k-1)\overline\lambda_f(T,c)},\qquad
k=\frac{\omega_2}{\omega_1}.
$$
Here $\overline\lambda_f=\lambda_f/T$, $\overline I_f=I_f/T$, and $\lambda_f$ is the Lebesgue measure of the set
$$
\bigl\{\gamma\in[\gamma_0,\gamma_0+T]:
f(\gamma)\ge c\bigr\}=A_f,\qquad
I_f=\int_{A_f}f(\gamma)\,d\gamma.
$$
It is established that this limit always exists for almost-periodic functions $f$.
\Bibitem{Fil96}
\by O.~P.~Filatov
\paper Evaluation of the limits of maximal means
\jour Mat. Zametki
\yr 1996
\vol 59
\issue 5
\pages 759--767
\mathnet{http://mi.mathnet.ru/mzm1770}
\crossref{https://doi.org/10.4213/mzm1770}
\mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=1445457}
\zmath{https://zbmath.org/?q=an:0887.34039}
\transl
\jour Math. Notes
\yr 1996
\vol 59
\issue 5
\pages 547--553
\crossref{https://doi.org/10.1007/BF02308823}
\isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1996VM73200012}
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This publication is cited in the following 7 articles:
O. P. Filatov, “Teorema usredneniya dlya pochti periodicheskikh funktsii”, Vestn. SamGU. Estestvennonauchn. ser., 2012, no. 6(97), 100–112
O. P. Filatov, “Averaging Theorem for Indeterminate Conditionally Periodic Motion”, Math. Notes, 90:2 (2011), 301–303
O. P. Filatov, “Teorema usredneniya i neopredelennye uslovno-periodicheskie dvizheniya”, Vestn. SamGU. Estestvennonauchn. ser., 2010, no. 6(80), 87–92
O. P. Filatov, “The existence of limits of maximal means”, Math. Notes, 67:3 (2000), 365–371
Filatov, OP, “Periodicity of optimal controls in the problem on the evaluation of limits of maximal averages”, Differential Equations, 36:5 (2000), 683
O. P. Filatov, “An asymptotic method for calculating limits of maximal means”, Math. Notes, 66:3 (1999), 348–354
A. C. Kairakbaev, O. P. Filatov, “An iterative method for calculating the limits of maximal means”, Comput. Math. Math. Phys., 38:10 (1998), 1591–1594